German kinetics vs iron will

German kinetics vs iron will DEFAULT

GERMAN KINETICS - Broadheads Made in Germany!

This is to all you bowhunters and customers of Original German Kinetics



Original German Kinetics and Silverflame is back!

Original German Kinetics - SilverFlames finally available

We are proud to provide you again with the real original Silverflame broadheads invented in 2003 by Markus Gross.

Redneckpoint, Thuringia, Germany took over sales, distribution and manufacturing. Ingo Kuhn, the owner, is a professional German Gunsmith and does the final assembly and quality inspection himself. He is a avid bowhunter and knows the quality is most important. Markus Gross is still on board and responsible for design and development.

Unlike the days of our ancient ancestors, modern bowhunting, as we know it today is certainly not something that is practiced out of a shear necessity for survival. However the deep passion and fascination for bowhunting, which the bowhunters of today exhibit, has been perhaps passed along through some genetic trait.
Sours: https://german-kinetics.com/

The main goals of this project are proposing kinetic models for the thermo-chemical oxidation/reduction of iron particle, and iron dust firing investigations in a CFD environment. First, the kinetics of the reduction of hematite to iron will be investigated. Then, the kinetic of the reverse (oxidation) step will be studied, bringing further considerations, such as the type of oxidation, or the heat release. Finally, the kinetic models will be transposed in a CFD environment for the simulation of iron flames, from a laminar case (Bunsen burner) to a turbulent one (high-pressure jet). Ultimately, this sub-project lays the basis for the accurate assessment of the dust firing efficiency.

Scientific questions:

  • How does the overall reduction/oxidation of a single particle evolve with time for a variety of gas conditions (temperature, pressure, composition, …) and solid ones (size, porosity, composition, …)?
  • How does the macroscopic flame structure evolve with varying gas to fuel ratio, particle size or temperature?
  • What are the effects of turbulence on iron dust oxidation?
  • What efficiency can be expected in an industrial reactor of iron thermo-chemical oxidation?

Picture: DLR

Picture: DLR

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    German Aerospace Center (DLR)

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    Broadheads | Selecting The Right One For Your Hunt

    mechanical broadheads pre test

    Written by John Lusk on . Posted in Blog, Bowhunting / Archery, Broadhead Reviews, Hunting

    It wasn’t long ago that broadhead selection was a fairly simple process… There just weren’t that many options available.

    Well, those days are gone. Now there are a plethora of choices due to so many different design variables.

    There are broadheads with 2 blades, 3 blades and 4 blades. (and even some with 8!)

    Expandable or fixed blades? Keep Reading!Fixed blade AND mechanical broadheads reviews videos are also further down the page!

    Then there are single bevel edges and double bevel edges, chisel tips and cut on contact tips.

    There are mechanical broadheads that deploy from the rear as well as those that deploy over the top.

    There are hybrids (both fixed and mechanical in the same head), stainless steels, tool steels, aluminum, and titanium all of various grades and properties.

    There are cutting diameters ranging from under one inch to over three inches and total head lengths of under one inch to over three inches and blade thicknesses of .020” to .080”.

    And, of course, prices ranging from one dollar per head to one hundred dollars per head… and so much more.

    closeup of toxic broadhead

    It never ceases to amaze me how creative broadhead manufacturers can get. The trick is knowing which head to use in a certain situation or type of hunt.

    So, bow hunters, how in the world do you make sense of it all? All the choices out there can make even an advanced bow hunter feel like a beginner. How do you know which heads are the best choices for you?

    We’ll cover a quiver-full of things to consider when choosing broadheads in the article, so if you want to jump straight to your topical interest, you can click the appropriate one below:

    Know Thy Broadheads

    While almost any head on the market today can “get the job done” with a good shot, it is still important to make sure you are using the right head for your bow and the game you are pursuing. After all the time, energy, and money you’ve invested in practice and preparation, your broadhead is where the “rubber meets the road.”

    broadheads thoughts pic

    Be sure that you choose a broadhead that will fly accurately at your maximum range.

    A little research and education can go a long way in making sure you are not disappointed after that hard earned shot. You will notice that I have provided some recommendations throughout this article. This is certainly not an exhaustive list, but I have personally tested each of these heads and found them to be among the best.

    Fundamentally, you must keep in mind what really matters in a broadhead. Regardless of the brand and the design, there are several crucial factors that really matter.

    Flight

    A broadhead should provide you with absolute confidence in its flight. Consider what your maximum range is and make sure you choose a head that will fly accurately at that distance—even with some wind, a racing heart rate, and shooting while a little off balance.

    Always make sure your bow is very well tuned (get help from a pro shop if you’re unsure) and you have the correct arrow spine for your bow’s poundage and draw length. Also, make sure the arrow spins true when the head is installed. You can spin it on your hand or on a table to confirm there is zero wobble to it.

    Furthermore, the smaller the overall profile of the head, in length and width, the more forgiving it will be in flight. This is why mechanicals are often a good choice for long distance shots.

    Keys: Lower profile (shorter and narrower) = Better Flight
    Truer Spin = Better Flight



    Edge Retention

    A broadhead should be be sharp and able to hold that sharpness after impact. How sharp it feels before it hits an animal doesn’t matter nearly as much as how sharp it is after it penetrates that first inch or two of hide, bone, and tissue.

    If the edge chips or bends, it will not cut and penetrate effectively. This is why blades should be thick enough, and the steel strong enough, to hold their edge well. Broadheads with higher quality Tool Steels like 41L40, S7, and A2 shine in this arena.

    (One of the most durable heads I’ve ever tested in terms of edge retention is the Valkyrie broadheads. You can see my tests on this head here).

    Keys: Thicker Blades = Better Edge Retention
    Higher Quality Steel = Better Edge Retention

    Ferrule Strength

    The ferrule of a broadhead must be able to withstand great force upon impact. I have had multiple heads, both fixed and mechanical, bend or break at the ferrule upon impacting an animal. That almost always spells disaster for a hunt.

    Quality materials and solid construction make a big difference. The shorter, thicker, and higher quality the material of the ferrule, the better it will stay in tact. I prefer high quality steel ferrules over titanium and aluminum for this reason.

    Keys: Shorter, thicker ferrules = stronger ferrules
    Higher quality steel Ferrules = Stronger Ferrules

    Cut Size

    A broadhead must have sufficient cut size to cause great tissue destruction while still ensuring deep penetration. With any animal I shoot at, my goal is to get as wide of a cut as possible while still providing a good likelihood of a pass through. Two holes will almost always provide a better blood trail than one hole. Given equal penetration, a wider diameter cut will slice through more tissue than a smaller diameter cut.

    In the past, I used a head with a cutting diameter of one inch and always got a pass through. However, I knew I could cut more tissue and still get a pass through. So, I increased the size of the cutting diameter of my heads, with great results.

    Likewise, I have used a head with a very wide diameter cut and gotten poor penetration and no pass through. Finding that sweet spot between the two extremes is my goal.

    Dead Ringer broadheads exit wound

    A Dead Ringer Broadhead exit wound through three ribs and shoulder blade of a hog.

    Match Broadhead To Your Quarry

    So, I will even change heads based on what animal I am hunting. If I’m going to be hunting turkey or other smaller animals like javelina, I use a very large cutting mechanical head, because that will cut a lot of tissue and still allow for a pass through. For a bigger animal like a wildebeest or elk, I like to use a smaller diameter cut to make sure I am getting deeper penetration.

    I have also found that when it comes to blood trails, cutting diameter is more important than total cut. Allow me to explain with an example:



    Diameter VS Total Cut

    A four blade head with a one inch cutting diameter will have a “total cut” of two inches. Likewise, a two blade head with a two inch cutting diameter will also have a “total cut” of two inches. However, with all other things equal (penetration and shot placement) the two inch cutting diameter head will typically leave a better blood trail than the one inch cutting diameter head—even though the same amount of tissue is cut.

    The reason for this is that a smaller diameter cut is more likely to close up with tissue while the larger diameter cut is more likely to stretch and open up even more. I have seen this proven over and over again.

    Another way to understand this principle is to “reduce it to the ridiculous.” Which head would you rather pass through your body: An eight blade head with one inch cutting diameter or a two blade head with an eight inch cutting diameter? Both will cut the same amount of tissue, but I would much rather have a one inch hole go through my body than an eight inch cut go through my body. Well, so would a deer!

    Keys: Greater Tissue Cut with Pass Through = Greater Blood Trail
    Greater Diameter Cut with Pass Through = Even Greater Blood Trail

    So before you read any further, keep in mind the fundamental goal in selecting a head: It should fly well, not break, holds its edge, penetrate deeply, and cut a lot of tissue. Strive to find that balance between cutting as much tissue as possible and still providing a good chance at a pass through.

    Now let’s examine some of the most important features of broadhead design. The more you understand about each feature, the more effectively you can decide what works best for your set up and your budget.



    Materials

    There are three basic types of metals used in broadheads: aluminum, titanium, and steel. Each has its advantages and disadvantages. Aluminum and titanium are lighter than steel, which is why many heads tend to use them. It is easier for a head to make it to the 100gr weight if aluminum or titanium are used.

    Aluminum

    Aluminum is not as strong as steel. The best aluminums hardened in the best manner are still only as strong as the weaker steels. And, some aluminums are much weaker than others. The best aluminum for broadheads is 7075, which is quite a bit stronger than 6061.

    So, if you are going to consider using a head with aluminum, try to find one made of 7075. One such head, is the Zeus broadhead, from New Era Archery.

    If the manufacturer doesn’t say which aluminum is being used, it is probably 6061. That doesn’t mean its “bad” but it does mean that it’s a bit “weaker.”



    Titanium

    Titanium is stronger than aluminum. As with aluminum, there are different grades of titanium. Just because a head is said to be made of titanium doesn’t mean it is using the top grade. Typically, if the manufacturer doesn’t state what grade it is, it is probably the weaker grade. While titanium is stronger than aluminum, it is not as strong as many steels. Both titanium and aluminum have less resistance to impact than many steels, so I prefer that a head that at least has a leading tip made of well hardened steel.

    contact tip vs chisel tip broadheads post testing

    Contact Tip vs Chisel Tip heads (post-testing).

    Steel

    There are many different varieties of steel and they are not all created equal. While steel tends to be stronger than titanium and aluminum, there are significant differences in the various types of steel. When it comes to broadheads, two of the most significant ratings of steel are Rockwell Hardness (the “hardness” of the steel) and Charpy V Notch Scoring (the steel’s resistance to impact).

    A steel may be very hard with a high Rockwell Rating, but may be very brittle and break apart or chip easily upon impact with a hard medium. Likewise, a steel can have a lower Rockwell Rating and not break apart, but may bend too easily.



    Most steel heads use a 420 stainless steel, hardened to a level that is not too hard and not too soft. From my testing, it is obvious that some manufacturers are more successful at finding that balance than others.

    There are also heads that are being made of tool steels and even very high end tool steels, such as 41L40, A2, and S7. With these premium steels, you will find a very high Rockwell hardness as well as a very high Charpy V Notch Score. Such heads will retain their structural integrity and razor edge far more effectively than typical stainless steels. They will cost a lot more money, but they are much more durable as well so they will last a long time.



    Premium Tool Steels

    In many of the tests I have done, I am continually impressed by how well premium tool steels keep their edge. While a typical stainless steel blade may become dull after cutting through 1/2” plywood, a head made of A2 or 41L40 or S7 will still be sticky sharp after cutting though that same board 5 times. That no doubt makes a difference in how well tissue, bones, and veins are cut.

    A duller head can often just bend veins over, but a head that is sharp all the way through an animal will effectively cut those veins, producing greater blood letting.

    Within steel heads there are also different ways the steel can be formed. Some use MIM (Metal Injected Molding), some are welded together, and some are machined. The machined steels tend to be much stronger than the MIM steels and welded models.



    Component Heads And Single Piece Heads

    There are also a couple different types of construction of the heads themselves—component heads and single piece heads. Each has their advantages.

    Component heads can be made with very tight specifications, as each piece is easier to construct than an entire head. These high specs can enable them to fly extremely well. They are then held together with some sort of interlocking design and bolt.



    The best component heads do not use bolts that are load bearing, but rather that interlock, and then held in place by the bolts.

    Single piece heads have the advantage of not being put together; they are literally one piece of steel. Thus, they tend to be more durable than component heads. But all single piece heads are not created equal.

    As mentioned earlier, if the head is machined out of a single block of steel it will tend to be much stronger than a head that is metal injected molded or welded.



    Blade Thickness

    All other things being equal, the thicker a blade is, the stronger it is. The thinner a blade is, the weaker it is. Thin blades may feel sharper out of the package, but they tend to lose that edge and bend or get nicked up more readily than thicker blades. I prefer blades that are at least .035” thick, but again, the thicker the better. When premium tool steels are used, a blade can still be relatively thin and still very strong.



    Chisel Tips vs Cut on Contact Tips

    Like most other broadhead topics, this one can lead to a pretty heated debate. In theory, chisel tips are more durable and cut on contact tips penetrate better. You can see this difference by pushing both a cut on contact head and a chisel tip head through a piece of cardboard. It will likely take noticeably less pressure for the cut on contact head to penetrate. However, upon impact with a hard medium like bone, the cut on contact tip is more likely to fold over than the chisel tip.

    From my testing, I only prefer a cut on contact head if is either a very thick two blade head made out of premium tool steel or a three blade single piece head, where all three blades come together to form the tip. Otherwise, the cut on contact heads are too likely to fold over. There are some chisel tips that are extremely sharp on their edges, like those of the QAD Exodus, or Wasp Dart for example. Those tend to have penetration closer to a cut on contact head but the strength of a chisel tip.



    Fixed Blade Broadheads

    Many people prefer fixed blade heads over mechanical heads because they are more durable and dependable. There are no moving parts and fewer things to break. Fixed blade heads typically come in either two, three, or four blade models. Let’s briefly examine each of those:



    Two Blade Heads

    These are a throwback to the proven designs of Native Americans and other similar societies around the world. They are simple, durable, accurate, and penetrate well. Two blade heads can either come in Single Bevel or Double Bevel Designs.

    fixed blade broadheads

    Fixed blade heads typically come in 2, 3, and 4-blade varieties.



    Single Bevel Heads

    A single bevel blade simply means that the edge of a blade is only sharpened on one side. A double bevel blade means that the edge of the blade is sharpened on both sides. There are advantages to each design. Typically, the choice between a single bevel or double bevel edge only comes into play with two blade heads.

    The advantage of a single bevel is that the angle of the blade creates a torsional force upon impacting a medium, causing it to rotate. If fletching is arranged helically, the arrow is already spinning. Then upon impact, a single bevel head will continue to spin inside an animal.

     This does a number of significant things. First, it creates a spiral wound channel. I typically find that the entrance hole of a single bevel head is not a slit, but rather a hole. The arrow is already spinning so much and is forced to spin more upon impact, creating a rounded entrance hole in the hide of an animal. The head continues to cut tissue not only in the direction the head is pointing, but also in the direction the head is spinning—thus cutting both inwardly and spirally.

    With internal organs, this can have a similar effect to spinning a fork when eating spaghetti, wrapping the noodles around the fork, then cutting them off. A twisting head can twist the organs and then cut them as the head moves forward. I have seen this happen inside an animal many times and the devastation is undeniable.

    Second, a single bevel head typically breaches bone very effectively. As the tip of a head enters a bone, the head also twists and causes that bone to split apart and not just get cut. Then the arrow passes through that split in the bone. This is especially significant when hunting very large animals such as Cape Buffalo. If a head cannot effectively breach that bone, penetration will suffer.

    A third way the single bevel head works is that due to its twisting inside an animal, it is not likely for the arrow to back out of an animal if there is not a pass through (try pulling one out of a target and you will see what I mean). Often times, heads are sharpened on the back edges to allow the heads to continue to cut tissue in all directions inside of an animal.



    Double Bevel Heads

    Double bevel heads do not have this spiraling effect. However, they can often penetrate more deeply for two reasons: First, they can be sharpened to a finer edge. Secondly, they are only cutting tissue in a forward fashion and not a twisting fashion. They will not typically breach large bone as effectively as a single bevel, they will not create a spiral wound channel, and the arrow can back out of an animal more readily than a single bevel. But, they will penetrate hide and tissue more effectively.

    As for which is better, it really does depend on your bow’s set up and your quarry. If you are generating lower kinetic energy and need penetration to be as deep as possible, a double bevel may be a better choice.

    If you have a bit more “normal” kinetic energy, or are hunting larger animals with heavier arrows, a single bevel will likely cause more damage to the animal.

    From my testing, the only concern I have with two blade fixed heads is the size of the entry and exit holes. If an animal does not expire quickly, you are going to be forced to follow a blood trail.

    Smaller diameter cuts do not allow the degree of blood letting that larger cuts do. There may be plenty of damage inside the animal, but the blood trail may be compromised.

    Recommended Single Bevel Heads: Bishop Archery (Bridgeport/Pipeline), Cutthroat Broadheads. Recommended Double Bevel Heads: German Kinetics Silver Flame, VPA, Steelforce

    Three Blade Heads

    There are some great strengths to using a three blade head, as evidenced by their popularity on the market. Three blade heads tend to make more of a “hole” than a slit. This makes the hole more difficult to close up and facilitates better blood letting.

    If the heads are a one piece construction with the correct angles, like VPAs or Bishops, you can easily sharpen two blades at a time by laying them flat on a stone and moving them back and forth, then rotating till all the blades are covered.

    Recommended 3 Blade Heads: QAD Exodus, Bishop (Bridgeport/Pipeline) Holy Trinity, VPA, Muzzy Trocar

    Four Blade Heads

    Some heads use a four blade design. Most of those have two primary blades, followed by two smaller, “bleeder” blades. Others use four blades that are all the same size, such as Slick Tricks, Wac’ems or Wasps.

    From my testing, I have come to prefer a wider cut three blade head over a four blade head with smaller, equal sized blades. That fourth blade does cut more tissue, but it also impedes penetration more, and the hole is not as big as that of a wider cut three blade head.

    A wider hole tends to produce a better blood trail than a smaller hole, whether it’s three blades or four. That being said, the four blade design of two larger blades and two bleeders is a very good option. They tend to be more forgiving in flight than a three blade head, all other things equal.

    Whether you want a two leading blade cut on contact tip or a chisel tip is another question as well. See the earlier section discussing the pros and cons of these two designs.

    Recommended 4 blade Heads: Iron Will, Trophy Taker A-TAC, Slick Trick Magnums, Magnus Black Hornet.

    Mechanical Broadheads

    Mechanical heads have come a long way in recent years. They have two primary advantages over fixed blade heads: Smaller surface area in flight (which allows them to be more forgiving in flight) and larger cut once the blades are deployed.

    For example, even with a very well tuned bow, it would be quite difficult to shoot a fixed blade head with a two inch cutting diameter and have it fly well. But with a mechanical, you can get that two inch cutting diameter in a small, great flying package.

    There are two primary styles of mechanical heads based on how the blades deploy upon impact.

    Over the Top Deploying

    The first mechanical heads to hit the market worked this way. The blades are on hinges and folds upward toward the tip of the head. They are either held in place by friction or a rubber band.

    Upon impact, the blades peel back like a banana would, opening up to their full cutting diameter. They will not open fully until after they have entered the animal, thus the entrance holes are basically the same size as the head in the closed position.

    Recommended Over the Top Deploying Mechanicals: Rocket Steelhead, NAP Spitfire, Wasp Jak-Knife, Dead Ringer Trauma, Grim Reaper

    Rear Deploying

    mechanical broadheads

    Mechanical heads (pre-testing). There is no shortage of them to choose from!

    In recent years, many heads have begun using various rear deploying mechanisms. With these heads, the blades swing open from the rear and are fully deployed by the time they reach the hide of an animal. Thus the entrance holes are the same size as the fully deployed blades.

    Both of these mechanisms have their loyal followings and both can work well on animals. I have successfully taken many animals with both. However, there are some observations worth noting.

    With over the top mechanicals, the entrance holes are small but the internal damage is great. They do tend to penetrate more deeply than rear deploying blades, simply because they cut less tissue upon entrance. If they pass all the way through the animal, the exit hole is the full size of the fully deployed blades. But if they do not pass all the way through, you have a small entrance hole and no exit hole. That spells a big problem for blood trails.

    With rear deploying mechs, the entrance hole will be great; it will be the size of the fully deployed heads. But because of that, penetration can be compromised because it has to cut through the hide with that wide cut. However, you can be confident you are going to have at least one big hole. Between these two styles, after all my testing I prefer the rear deploying mechanical heads by a large margin.

    Recommended Rear Deploying Mechs: Rage Hypodermic and Trypan, NAP Killzone, G5 Deadmeat

    Hybrid Broadheads

    Several different manufacturers have come out with hybrid heads, which are a combination of both a fixed blade and a mechanical head. There is typically a smaller two blade fixed head followed by a larger cut of mechanical blades.

    I have taken a number of animals with these and tested them quite a bit. They certainly have their niche. The only downside is that you will want to make sure you have enough kinetic energy to drive all those blades deeply into an animal. Again, I prefer the rear deploying mechanical blades in a hybrid head. If they are over the top deploying, you will not get a very big entrance hole and an exit hole will be fairly difficult to achieve due to the large cut.

    Recommended Hybrid Heads: Bloodsport Archery Gravedigger, Muzzy Hybrid Trocar HB-Ti.

    Conclusion

    Selecting a broadhead can be a pretty daunting task. And it gets extra confusing when all of your buddies each have their own strong opinions based on their personal experience from the last season. But you owe it to yourself and to the animal to make the most informed decision you can about which head is best for your purposes. Hopefully, this article will help you to make a bit more sense of the options and choices available.

    For specifics on other broadheads that may not be listed in this article, click on the names below:

    Please also check out my YouTube Channel as well, Lusk Archery Adventures, to see videos of broadhead tests and over 50 hunts with those heads as well. And don’t hesitate to contact me with any questions through the channel.

    John Lusk archery goat

    (Learn about N1 Outdoors archery apparel and other hunting and fishing apparel designs.)


    John Lusk

    John Lusk is an avid bowhunter and broadhead fanatic. He has taken well over 100 big game animals with his bow all over the US, as well as Canada and South Africa. He puts his Engineering degree to use in his broadhead testing and has tested over 50 different broadheads. He has written articles in a dozen different archery publications, appeared on several hunting TV shows, and has well over a million views on his YouTube Channel: Lusk Archery Adventures. There you will find more than 70 videos of his hunts and extensive broadhead tests. When he is not shooting his bow, John serves alongside his wife as the Pastor of the Des Moines Church of Christ, in Des Moines, Iowa.

    Sours: https://n1outdoors.com/broadheads/
    GERMAN KINETICS BROADHEAD AT 100 YARDS

    Samurai vs. Maasai vs. Overkill

    enkriss said:

    In that case stay away from that AUS4 steel on the cheap ones it’s crap. Won’t hold an edge.

    Click to expand...

    I don't doubt the superior edge holding of the regular grizzly stick broad head over the overkill series, I not sure it merits consideration for hunting purposes. I say that based on a recent Ranch Fairy video where he discussed and showed the difference between 2 different tuffheads he had shot through pigs and 2 that hadn't been shot and were hunting sharp. I know he takes his sharpening seriously and there was a striking difference. To me that illustrates the point that resharpening/touching up will be a necessary step before every hunt.
    I also am under the impression that the softer steel of the overkills will take an edge easier but that may just be my own misguided notion.

    Also I have the 125gr maasai overkills that I'll be shooting this year. If you go with theaasai's I recommend the staysharp "C" series sharpener for keeping them sharp also. It made taking mine from sharp to scary sharp a pain free and easy process.

    Sent from my Pixel 3 using Tapatalk

     

    Sours: https://saddlehunter.com/community/index.php?threads/samurai-vs-maasai-vs-overkill.40462/

    Iron will german kinetics vs

    Leaching of iron from copper tailings by sulfuric acid: behavior, kinetics and mechanism†

    Lei Tao,a   Langlang Wang,a   Kanghuai Yang,a   Xueqian Wang, ORCID logo *a   Lu Chen*b  and  Ping Ninga  
    Author affiliations

    * Corresponding authors

    a Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, PR China
    E-mail:[email protected]
    Tel: +86 13888183303

    b Faculty of Business Management, Yunnan Communications Vocational and Technical College, Kunming 650500, PR China
    E-mail:[email protected]

    Abstract

    Copper tailing is a widespread and intractable solid waste in copper production. Traditional leaching and recovery technology for copper tailing focuses on copper but neglects the leaching of iron. With the increase in applications and demands of iron-containing materials for environment, understanding the leaching behaviors of iron can promote the utilization of copper tailings. In this study, the kinetics and mechanism of the leaching of iron from copper tailings using sulfuric acid were studied. Under optimal conditions (40 °C, sulfuric acid concentration of 0.53 mol L−1, stirring speed of 400 rpm, solid/liquid ratio of 1 : 10 and leaching time of 120 min), 66.45% of Fe, along with 65.32% of Zn and 59.95% of Cu, were leached from the tailings. The leaching of iron was confirmed to be controlled by solid-film diffusion. The reaction orders for sulfuric acid concentration, solid/liquid ratio, and stirring speed were found to be 0.85, −0.70, and 0.40, respectively. Results from XRF, XRD, and SEM indicated that oxides (including CaO, CuO, and ZnO) were leached first, after which Fe2SiO4 was preferentially reacted compared to Fe3O4. The accumulation of CaSO4 and SiO2 inhibited the further leaching of iron.

    Graphical abstract: Leaching of iron from copper tailings by sulfuric acid: behavior, kinetics and mechanism

    This article is Open Access

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    Supplementary files

    Article information

    DOI
    https://doi.org/10.1039/D0RA08865J

    Article type
    Paper

    Submitted
    18 Oct 2020

    Accepted
    11 Jan 2021

    First published
    02 Feb 2021

    This article is Open Access
    Creative Commons BY-NC license

    RSC Adv., 2021,11, 5741-5752

    Leaching of iron from copper tailings by sulfuric acid: behavior, kinetics and mechanism

    L. Tao, L. Wang, K. Yang, X. Wang, L. Chen and P. Ning, RSC Adv., 2021, 11, 5741 DOI: 10.1039/D0RA08865J

    This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes.

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    Sours: https://pubs.rsc.org/en/content/articlelanding/2021/ra/d0ra08865j
    iron will wide solid broadhead ballistic gel test - bco review -
    Day Six Broadhead Review

    Looking for a Day Six broadhead review?  There aren’t many since they are one of the newest (and most expensive) options on the market.  That’s a shame because I think they also happen to be one of the best options around. But is it right for you? Read on.

    When the Day Six launched their Evo broadheads last summer I was intrigued based on my positive experiences with the Day Six HD Arrows (review here).  I picked up a 6 pack before last season and was fortunate to actually put one to good use… but let’s not jump ahead.  First, here’s a quick overview:

    Rather a video review? Here you go:

    Overview & specs

    The Evo broadhead has all the hallmarks of a great elk broadhead: minimal surface area, solid construction, and an emphasis on penetration. Add aerospace tolerances, top shelf materials, plus 100% USA production and it’s clear these are designed with perfection, not cost, in mind. Here are some quick specs:

    • Day Six Evo broadheads
      • $89 / 3 or  $190 / 6 with included SKB case
      • 1 1/16” wide main blade and 1/2” bleeder blades
      • S30V stainless steel blades, hardened stainless steel ferrule
      • 100 or 125gr
      • $33 for set of 3 replaceable blades + screws
      • Other options:
        • Evo-X: 1 ¼” blades, 125 of 150gr (blades interchangeable with Evo!)
        • Evo XL: 1 ¼” blades, 200 or 250gr

    It’s hard to overrate that S30V steel.  I won’t dive into why powder steel is so amazing here (see the Benchmade Altitude review for more) but there is a reason it’s a standard in high end knives.  It’s not common in broadheads due to cost but it’s an extremely sharp and durable steel.  It also happens to be nearly rust proof, which we’ll dive into later.

    Day Six operates on a direct to consumer model so the only place you can buy these is straight from their website.  While that business model means that you might not have heard about them, it also means they can pass the middle-man costs on to you as savings.  We’ll talk about alternatives later, but I think $89 is actually a pretty fair price considering what you get.

    There are a lot of subtle details to the Evo broadhead design, but let’s dive into them in the pros/cons.  Here are my thoughts:

    My Day Six Broadhead Review (Pros & Cons)

    I tested the Evo 125gr broadhead over the course of last season and was fortunate to actually kill a bull with one on opening day in August (first elk ever killed with a production head?  It’s possible). Here’s what I liked and didn’t like:

    Pro: Accuracy, Accuracy, Accuracy

    Many broadheads are so long or wide that they act like rudders on the front of your arrow.  The short, relatively narrow design of the Evos leads to phenomenal accuracy and makes them easy to tune.  They’re up there with the best fixed heads I’ve ever tested which is impressive given that they have non-vented blades.

    Pro: Best in class penetration

    I’m a strong believer that a complete pass through (read: two holes) is far better for elk hunting than a wider cut.  That’s especially important for folks with low poundage or short draw bows. While fixed blades will always penetrate better than mechanicals, there are two unique design aspects of the Day Six broadheads that make them phenomenal penetrators: their blade angle and blade curve.

    If you dive down the rabbit hole of broadhead design, you’ll see a lot of claims that a 3:1 length:width ratio is best for broadhead penetration. It all boils down to the blade angle: a blade does a far better job cutting when you slide something along it than when you “push” it through something.  Therefore the “steeper” the broadhead edge is (closer to being parallel with the arrow itself) the better it penetrates.

    So why aren’t these 3″ long? Well a long broadhead is great for traditional archers but the amount of drag they create wouldn’t be very accurate out of a compound bow.  By slightly curving the blade edges, Day Six was able to create a short design that acts the same as a much longer straight edge blade.  Couple that with a very relaxed bleeder blade angle and you have a broadhead that penetrates like crazy. Don’t believe me? They actually won the Born & Raised outdoors broadhead test for penetration.

    Pro: Great tolerances

    Broadhead tolerances really boil down to two measurements: straightness and weight.  The Evos were fantastic at both. All six broadheads were within 0.3 grains of 125gr and it was impossible to detect any wobble with a naked eye.  Alignment was also perfect with replacement blades, which means the underlying system is solid. You’d expect great tolerances at this price and it’s nice to know the broadheads live up to the hype.

    Pro: Perfect practice

    I personally think one of the most important features in a broadhead is the ability to practice with the exact same broadhead you’ll use to hunt.  Why? Each individual broadhead and arrow combo is unique, so it’s critical to know the actual combination you’re using is accurate.  Sure, you can replace blades or use a practice head, but i’ve still seen slight changes in impact after that.

    Since the Day Six Evos have great edge retention I’d be comfortable shooting an arrow several times, stropping it (or not), and then using it in the field.  That level of confidence is priceless.

    Pro: Sharp!

    S30V steel is capable of getting razor sharp and these don’t disappoint.  No need to do anything to these straight out of the package. I was also impressed at the edge retention after shooting them into a foam target 10-20 times.  I’d still strop them back to razor sharpness, but you could easy use them “as is”.

    Pro: Quiet

    A Day Six broadhead review is complete without mentioning their silent design. No arrow is dead silent but the solid blades (read: no vents) on these are very quiet.  I haven’t found that to be a big deal with elk but I’ll take every advantage I can get. On the other hand, these are perfect for axis deer since they are about as jumpy as it gets!

    Pro: It clearly works on elk

    As I mentioned, I was lucky enough to use the Day Six broadhead to on an elk last year.  The shot ended up being through a tiny gap in the trees at 32 yards from a sitting position.  The arrow was a clean pass through and the elk died within 100 yards. Textbook performance, and a testament to the benefits above.

    I will say the broadhead hit a rib and deflected out the bottom of the animal, which isn’t that unusual (and why I don’t recommend mechs!).  The blood trail was plenty fine and clearly the results speak for themselves.

    Con: Resharpening + replacement cost

    I had to think hard to find something I didn’t like here and my only complaint is that they aren’t the easiest broadheads to resharpen.  Most of that is due to features I wouldn’t change (curved blades, relaxed blade angles, etc) and is also the same as 80% of the fixed blades on the market.  That said, you’ll have to remove the blades and freehand these if they really get dull (stropping is plenty fine for target shooting, even some hunting).

    I’d love to see a micro “V-notch” style sharpener for these but since replacement blades are only $11 I’d predict that most guys will just swap blades out anyway.  That’s totally fine if you’re shooting 1-2 elk a year. If you’re shooting 20+ deer in Alabama, you might want to use another set of 3 blade broadheads that you can touch up on a stone.

    I intentionally didn’t put price as a “Con” here because I think you actually get fantastic value with these heads.  That said, replacing these isn’t cheap and I would think twice about winging one of these at a turkey for example. The decision is up to you but I think they’re a worthwhile investment if you’re focusing on elk.

    Tips & tricks

    You can swap in the 1 ¼” Evo-X blades with your Evo broadheads.  That’s a nice benefit for you guys that want a wider head for whitetail that can be converted for use with elk. It will add 25 gr of weight, so you’ll have to retune, but at least it works. You can also carry extra blades into the backcountry as a lightweight way to have an “extra” broadheads.  The ferrule is so strong on these I highly doubt you’d ever see one bend even if you ruined the blade on a rock.

    Given how easy and precise it is to swap blades on these, I bought a set of backup blades and designated two as high volume practice blades.  I don’t worry about resharpening them and simply swap the other blades back for a shot or two before I head out.

    All that precision is going to be completely worthless unless you spin test your arrows (and better yet, spin test your inserts when you build your arrows!).  If you’re going to spend $30+ for a broadhead, do yourself a favor and get a Pine Ridge Arrow Spinner for $20 and make sure they spin true.

    Day Six Broadhead review

    Alternatives

    In some ways I hate reviewing broadheads because emotions tend to run strong here.  Why? There are literally hundreds of good heads and honestly a sharp stick would kill an elk if put in the right spot.  If you’ve had great results with a head you’re already using, I say stick with it, and don’t interpret this as invalidating its design.

    That said, if you’re looking for the best broadheads made for elk it pretty much boils down to these and the Iron Will Broadheads.  The Solids, German Kinetics, and Bishops are nice, but they can’t beat Day Six or Iron Will on the ratio of accuracy to strength in my opinion.  

    The Iron Will broadheads are basically the same design as the Day Six (and many other broadheads before those two existed).  The biggest difference is penetration, blade steel, and rust resistance. The Day Six’s will penetrate better with their curved (vs tanto) shape and relaxed bleeder blade angle.  The A2 steel in the Iron Wills will likely hold an edge a bit better and be a tiny bit stronger. That said, A2 steel is not stainless and is definitely known to rust. For me, that’s pretty annoying since the last thing I want to do is maintain my broadheads by oiling them.  In the end, they’re both amazing options and you’d be happy with either.

    Summary: Day Six Broadhead review

    If you’re looking for the best broadhead for elk regardless of cost, the Day Six Evo should be one of your finalists.  Their unique design provides fantastic accuracy and penetration in a compact package. Quality S30V blades mean top tier edge retention and the overall tolerances are some of the best in the business (made in the USA!).  The Evos are also very rust resistant and allow you to practice with the same broadhead you hunt with, which are big pluses for backcountry hunters. The design does make sharpening a bit more difficult but that’s a tradeoff that has to be made to get this level of performance. At almost $30 a head they’re not cheap but I think that’s a fair price given the value they deliver.  

    Would I buy them?  Yup, they’re my primary broadhead when I’m chasing elk or when I care about arrow noise (aka Axis deer hunting).  If you want the best you can buy and value rust resistance + penetration above all else, these were made for you.  If you choke up at the thought of losing a $30 head there are plenty of great options that won’t break the bank. Let me know your thoughts on the Day Six Broadhead review below and sign up to stay tuned for more reviews coming soon.

    Sours: https://www.baxterbowman.com/day-six-broadhead-review-evo-125gr/

    Now discussing:

    V Series Broadheads

    from 109.95

    Engineered to be as reliable as science allows, the Iron Will V Series broadheads were made to hunt as hard as you do. So when you're at full draw with the trophy of a lifetime downrange, you can count on your broadhead to finish the job. Vented, low-profile, and perfectly aligned A2 Tool Steel blades ensure precision long-range accuracy. A Grade 5 Titanium ferrule (lighter heads) or 17-4 PH hardened stainless steel ferrule (heavier heads) provide a firm foundation that ensures your arrow’s momentum drives through impact instead of flexing and displacing energy. And because you rely on it at your moment-of-truth, we stand behind it with a Lifetime Guarantee.

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    Size Options

    100-200 Grains
    Standard Threads, Deep Six, or Snyder Core
    Most broadheads use Standard (8-32) Threads.

    Deep Six Threads are designed to fit Easton 4mm shafts with HIT inserts that use the Deep Six thread pattern. Only purchase Deep Six Threads if you plan to use them with Easton 4mm shafts with Deep Six HIT Inserts.

    The Snyder Core System, engineered in conjunction with Aron Snyder, must be either glued in or screwed in at a deeper depth inside the arrow. Choose a Snyder Core option only if your arrows are set up to align with the Snyder Core System.

    Cutting Diameters

    Main Blade: 1 1/16"
    Bleeder Blade: 3/4”
    The vented, low profile main blade minimizes wind effects and maximizes big game penetration, so you can hit your mark and bring home more than a story. We added the bleeder blade to unzip a larger wound channel for easy blood tracking.

    Materials

    .062” Thick Vented A2 Tool Steel Blades with Proprietary Hardening Process
    Iron Will broadheads are engineered to be extremely sharp and stay that way. This produces edges that remain honed all the way through the target, requiring less force for a complete pass-through. Additionally, unmatched edge retention and sharpened back bevels deliver your trophy with maximum internal hemorrhaging for great blood trails. Easily resharpen these broadheads for reliability hunt after hunt.

    Hardened Ferrules
    Hardened Ferrules (titanium for lighter heads and stainless steel for heavier heads) ensure the broadhead stands firmly aligned with the arrow at impact. This aligns the arrow’s momentum to drive through the animal instead of bending and displacing the momentum sideways.

    Technology

    Patented Tanto Tip
    Iron Will’s patented blade geometry includes a Tanto Tip on the end of each broadhead, which is utilized for maximum impact strength. By widening the tip as compared to more traditional broadheads, extra bone splitting strength and rigidity is added, preventing the bending or breaking that saps momentum and stops arrows in their tracks. Additionally, the Tanto Tip reduces surface area for greater accuracy at long distances. US Patent 10,054,409

    From the Lab

    Magnified Iron Will Broadhead
    Magnified Cheap Broadhead

    Broadhead Blade Impact Toughness

    Broadhead Impact Toughness.png

    Broadhead Blade Hardness

    Broadhead Blade Hardness.png

    Ferrule Strength

    broadhead ferrule strength.png

    From the Field

    bow killed moose

    “My bull was mature, large bodied and carried a 61” antler spread. I shot him twice at full broadside and both were kill shots. First shot was a double lung pass-through at about 35-40 yards. That broadhead went through him so fast he didn’t even blink. Second shot, about 15 seconds later at 25-30 yds, again a double lung pass through. The second arrow passed through him with such remaining speed/energy that it completely split a 2” sapling 20 feet on the other side of him. Bull trotted about 60 yards into the middle of a small river, stood there about 10-20 seconds and dropped. ”

    — JL

    Frequently Purchased Together

    Sours: https://www.ironwilloutfitters.com/gear/v-series-broadheads


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