Questions tagged [metallurgy]

Chemical and physical characteristics of metals and alloys.

Filter by
Sorted by
Tagged with
-1 votes
1 answer
70 views

Why is silver considered a "type 1" metal although it has multiple oxidation states?

I noticed that the metals I learned were "type 1" back in early chemistry class as they have one oxidation state including silver, aluminum, zinc, and cadmium. However, those metals weren't ...
0 votes
0 answers
40 views

Separate aluminium from brass threaded bushing without affecting the brass

I wanted to separate aluminium from brass threaded bushing without affecting the brass. I also suppose that brass isn't the brass but it's a phosphor bronze. Does brass and phosphor bronze amalgamate ...
0 votes
2 answers
156 views

Which gases(or gas) are evolved in the leaching of Galena(PbS) with conc. Nitric acid? [closed]

I want to know the gases produced(primarily nitrogen oxides) in leaching of Galena in nitric acid and the effect of concentration of nitric acid on the gases evolved. I found papers about the ...
1 vote
1 answer
20 views

Is anodizing of mixed metals (aluminium and cooper) possible?

I'd like to blacken my Noctua NH-P1 passive cooler, made from an aluminium fins and copper heatpipes. Since thermal dissipation is key in my build, I thought about anodizing it, instead of spray paint ...
1 vote
0 answers
24 views

Calculating pourbaix diagram of Fe-H2O system at different temperatures

I have been trying to calculate the pourbaix diagram for Fe-H2O at different temperature for my high school research but I am facing a lot of problems. I have several question regarding the ...
-2 votes
2 answers
83 views

What is the reason for extracting copper from copper pyrites and not iron?

Why can copper be extracted from copper pyrites ($\ce{CuFeS2}$) but not iron? Is there some intuitive logic behind it?
0 votes
0 answers
46 views

Gold cyanidation process

My chemistry book says the following: In the metallurgy of silver and gold , the respective metal is leached with a dilute solution of $\ce{NaCN}$ in presence of $\ce{O2}$ as a result of which the ...
  • 154
-1 votes
1 answer
49 views

Can a plain sheet of stainless steel adhering to the 316 grade be regarded as food safe at every finish level?

My question is not purely about chemistry but it definitely involves it. I was looking for a while to buy a food-grade stainless steel plate that would fit my home pizza gas oven (to have the dough ...
  • 27
4 votes
1 answer
251 views

Ellingham diagram/graph for tungsten

I've recently come across one of the methods to form tungsten carbide($\ce{WC}$) from wolframite ($\ce{(Fe,Mn)WO4}$) by using carbothermic reduction which was supposedly one of the first methods for ...
0 votes
1 answer
46 views

Aluminum Alloy with most alkaline resistance [closed]

Previously i asked this question in Engineering SE: What aluminum grade is the most resistant to corrosion in alkaline environment? Some input from others seem indicating that no mass-produced ...
  • 1
0 votes
0 answers
37 views

How to determine the visual properties of a specific steel compound?

The material that is described in a paper by Li et. al.[1] is interesting to me, but they don't go into any details on what the end result would look like visually. Out of curiosity, I was wondering ...
  • 1
1 vote
1 answer
37 views

How to Improve Phosphoric Acid 85% leaching of Natural Titanium Rutile without increasing impurity?

Using magnetically separated natural titanium rutile from a mine in South Africa to leach titanium for oxide production using H3PO4 85%. (The reason for using H3PO4, is that it separates out any Fe ...
  • 19
1 vote
1 answer
57 views

Dehydrating hydrated Magnesium chloride

I came to know that hydrated Magnesium chloride $\ce{MgCl2.6H2O}$ is dehydrated not directly by heating as it gets hydrolysed to $\ce{MgO}$ . But instead it is dehydrated by passing through $\ce{HCl}$ ...
  • 77
4 votes
0 answers
25 views

The role of 2-nitrophenol in tin etchant (aqueous mixture of 2-nitrophenol and NaOH)

Aqueous mixture of 2-nitrophenol and NaOH is a time-honored etchant that dissolves tin-rich alloy and retain the intermetallic compounds from the tin. I wonder the role of 2-nitrophenol in the etching ...
  • 41
10 votes
3 answers
2k views

How can steel be so different from iron, even if amount of carbon is small?

Perhaps I am too naive, but I am having a hard time visualizing how even 'high-carbon' iron and steel alloys are maybe, at most, about four percent carbon by mass, which still means only one (smaller) ...
  • 1,659
1 vote
0 answers
126 views

Natural preservatives of ink

Would pure compounds like thymol, carvacrol, and cinnamaldehyde work as preservatives of fountain pen ink? I'm specifically interested in three properties - Prevention of growth (mostly fungal) in ...
  • 11
1 vote
2 answers
323 views

Extraction of copper from chalcopyrite

During the extraction of copper from chalcopyrite ore, the ore ($\ce{Cu2S.Fe2S3}$) is heated to form $\ce{Cu2S}$ and $\ce{FeS}$. Then during smelting it reacts with $\ce{O2}$ to form $\ce{Cu2O}$. Then ...
1 vote
1 answer
140 views

Why do mineral particles become wet by oils while the gangue particles by water?

In my textbook, NCERT Chemistry for class 12, it is mentioned that one of the principle of froth floatation method is the following: The mineral particles become wet by oils while the gangue ...
4 votes
1 answer
212 views

Why is the term "nascent nitrogen" still used in metallurgical industries?

Continuation of Why do nitrogen-containing organic compounds give N2 as the combustion product? (comment converted into question) Nascent state is an obsolete theory in chemistry and is discredited. ...
  • 22.9k
7 votes
2 answers
974 views

How to separate Cu and Ni from alloy containing different metals such as Al, Cu, Ni, (Zn, Pb, Sn < 5%)?

I have an alloy containing different metals such as Al, Cu, Ni, (Zn, Pb, Sn, Ag, Si in small amount < 5%). How can I separate Cu and Ni from this alloy? I tried to dissolve alloy in sulfuric acid, ...
  • 89
0 votes
1 answer
503 views

Why is the only natural source of radium compounds uranium minerals?

A common mineral of barium is barytes, or barium sulfate ($\ce{BaSO4}$). Because elements in the same periodic group have similar chemical properties, we might expect to and some radium sulfate ($\...
1 vote
1 answer
140 views

What is the alloying composition of the Zinc-Platinum System?

My research team and I are working on a bimetallic alloy consisting of Zinc and Platinum. We have looked for papers regarding the composition of Zinc-Platinum alloy. But there aren't many papers out ...
-1 votes
1 answer
315 views

Why same metal salt is required in electrolytic refining?

Why we use same metal salt in electrolytic refining? Ex. For $\ce{Cu^2+}$ if we take suppose $\ce{FeSO4}$ so there are 2 ions ready to react on cathode ie $\ce{Fe^2+}$ and $\ce{Cu^2+}$. But from a ...
2 votes
1 answer
307 views

Why is the formation free energy of carbon dioxide almost constant in Ellingham diagrams?

While reading about Ellingham diagram in my textbook, I noticed that for: $\ce{C_(_s_) + O2_(_g_) -> CO2_(_g_)}$, the standard Gibbs free energy ($\ce{\Delta_fG^\circ}$) doesn't seem to vary with ...
  • 499
2 votes
1 answer
136 views

Why are calcination and roasting processes carried out at a temperature just below the ore's fusion temperature?

I had read about the two important methods used for the concentration of an ore - Roasting and Calcination. I have a doubt regarding why both the methods are carried out at temperatures not above the ...
  • 499
2 votes
1 answer
98 views

How thick is the colored oxide layer on heat treated stainless steel? [closed]

When stainless steel is welded, or just heat treated, it will develop a thicker oxide layer, which in some cases is is rainbow colored, but can become so thick as to appear almost black. From the ...
  • 12.6k
1 vote
1 answer
82 views

Why does Cody use Litharge? [closed]

In many of the precious metal refining videos Cody (Cody's Lab) takes the sample with the precious metal and puts Litharge into it. After heating it in the furnace, while pouring it out the molten ...
8 votes
1 answer
497 views

Why are rare earth metals and platinum group metals are often found clustered together in ores

Rare earth and platinum group metals are often found clustered together in the earth's crust. Mining for platinum, for instance, also yields Rhodium and Ruthenium belonging to the same group. Likewise,...
2 votes
1 answer
160 views

Roasting of galena

In the metallurgy of $\ce{Pb}$, Galena is first concentrated by froth floatation process. It is then partially roasted to and self reduced to obtain $\ce{Pb}$. Why is galena only partially roasted(...
  • 377
0 votes
0 answers
42 views

Calculating change in Gibbs Free Energy for a specific type of problem

Can anyone describe what is going on here? $$Si(liq.)=Si_{(1 weight percentFe)}$$ I have come across this statement quite a few times in Metallurgical Thermodynamics.All that they ask for is change in ...
1 vote
1 answer
51 views

Properties of inconel [closed]

I am doing a project on the physics of the spaceX raptor engine. I believe it is made out of a certain type of inconel alloy. I want to understand why this alloy has the properties that it does, but I ...
  • 25
7 votes
2 answers
455 views

How to refine manganese metal from manganese(IV) oxide found in batteries? [closed]

I opened up some lantern batteries, and inside there's $\ce{MnO2}$ powder, carbon rods, and zinc casings, and other stuff that I don't know what it is exactly. I scraped out $\ce{MnO2}$-containing ...
-1 votes
1 answer
163 views

Thinking of reducing aluminum hydroxide with magnesium

Is it possible to reduce aluminum hydroxide to aluminum metal by using a sacrificial magnesium electrode in a single displacement reaction? I checked my revision of redox charts and it looks like it ...
  • 107
6 votes
1 answer
290 views

Origin of the 15% difference limit between solute and solvent atom radii in the Hume-Rothery rules

According to the Hume-Rothery rules for the substitutional solid solutions the atomic sizes of the the solute and solvent must not differ by more than 15%. Why should it be so?
1 vote
1 answer
104 views

Are there any sulfides, sulfates, carbonates that cannot be dissolved by aqua regia? [closed]

I was looking into these specific minerals: arsenopyrite, pyrite, chalcopyrite, barite, calcite, dolomite. I investigate issues with tellurides not showing expected gold concentrations.
  • 13
0 votes
0 answers
454 views

Are Alloy Compositions Given in Weight Percent or Atom Percent

Often times I see alloys described like this, Lockalloy is an alloy that consists of 62% beryllium and 38% aluminum Are the precentages mentioned here in weight percent or atom percent? Is there a ...
1 vote
2 answers
53 views

Thermal properties of aluminium alloy 6063 [closed]

I am looking for the operating temperature range both in a cold and hot environments (minimum and maximum operating temperatures) for aluminium alloy 6063. I'm new to finding this kind of information ...
-1 votes
1 answer
44 views

Can a metal which contains impurity of another metal that is more reactive than itself be electrorefined?

So I know that cathode is made of pure metal and anode of impure. For example take Cu. Cu will be oxidised to Cu+2 at anode and will deposit at cathode. But now if it contains impurity of , let's say, ...
1 vote
1 answer
791 views

What's the difference between Zinc Ascorbate and Zinc Gluconate?

I've been looking at a dental product for pets, called MAXI/GUARD Oral Cleansing Gel and it states it uses zinc ascorbate/taurine, however in the ingredients I found elsewhere it instead lists zinc ...
  • 39
0 votes
1 answer
38 views

Manufacture an artifact with compression

Room-temperature superconductivity has finally been demonstrated, as reported by Quanta (and others), with the caveat that it requires compression of the substrate at nearly 2 Mbar. Obviously, this ...
1 vote
1 answer
256 views

Why is there carbon lining on the steel vessel in Hall Heroults process?

I read This answer, and completely understand that why graphite anode is used , but I have read that the vessel acts as the steel cathode but with lining of carbon. What is the need of this carbon ...
  • 139
0 votes
2 answers
390 views

What explains the case hardening color effect?

Year 11 chemistry student here. I'm curious about how the case hardening effect works on metals. I know that when the electrons gain an energy 'level' or lose an energy 'level' they emit light at ...
1 vote
2 answers
179 views

What lab equipment did Marie Curie use to isolate radium?

My experience in growing crystals for condensed matter physics has been sealing grams of material in ampoules which get heated in laboratory furnaces, so I don't have the experience to understand how ...
4 votes
1 answer
2k views

How does liquid gallium interact with a gold leaf

I would like to know what happens when gold leaf comes into contact with liquid gallium. Will the gold dissolve into (alloy with) the gallium, wet the gallium or have no reaction with gallium? The ...
0 votes
0 answers
153 views

What is the minimum thickness for stainless steel crucible to melt aluminum

I am planning to make a stainless steel crucible (air-tight) to melt aluminum. Aluminum is known to oxidize in presence of air. I therefore want to create a custom crucible made with sheet metal ...
  • 151
4 votes
1 answer
54 views

Home foundry — melting aluminum, mitigating undesirables

I am going to be melting aluminum cylinder head and some soda cans in the home foundry. I am aware the sulphur and the hydrogen present in the melt can make aluminum prone to cracks and brittle. Are ...
  • 151
1 vote
0 answers
170 views

Is melting aluminium in the presence of carbon dioxide desirable?

So aluminium cans melting is prone to formation of aluminium oxide due to presence of oxgygen and thin sheet of aluminium (large surface area). To mitigate this I can design a cruicible which is ...
  • 169
4 votes
2 answers
368 views

Why does an mercury ore exist as HgS?

Cinnabar($\ce{HgS}$) is one of the most common ores of mercury. Why does it not exist at $\ce{HgO}$ or some other such compound? Is there any reason for why it is so prevalent? Does it react less ...
  • 55
3 votes
1 answer
63 views

Side product obtained in reduction of cuprous oxide with carbon

So my book sates that in the extraction of cuprous oxide, the following reaction takes place. $$\ce{Cu2O + C -> 2 Cu + CO}$$ This makes sense to me, if it is seen as the following two reactions ...
1 vote
0 answers
29 views

Can metal matrix composites be alloyed after their creation?

I've done a little research on metal matrix composites (MMCs), purely for fun and out of interest. Different types of metal powders are combined with reinforcement materials, to produce a reinforced ...
  • 155

1
2 3 4 5 6