• What Are the Uses of Sulphuric Acid?

    Sulphuric acid is used in the processing of iron, copper and steel to clean the metal and prevent oxidation before it is plated with tin or zinc. This is known as ''pickling''. Two examples of using sulphuric acid in this way are to make cans for food and to supply the correct metal for sale to …

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  • Chemical Cleaning of Coins

    The following compounds involved in chemical cleaning of coins are capable of reacting with coinage metals: • Acids (Hydrochloric acid, Sulfuric acid, Nitric acid, Vinegar, Lemon and Tomato juices, etc.) CAUTION: DILUTION OF SULFURIC ACID MUST ALWAYS BE DONE BY POURING ACID …

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  • Chemicals Used in Mining

     · Sulfuric acid. Sulfuric acid is a toxic chemical used in copper mining. It is also a byproduct of many kinds of mining, mixing with water and heavy metals to form acid mine drainage. Sulfuric acid smells like rotten eggs. Contact with sulfuric acid can cause burns, blindness, and death.

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  • How To Clean Silver Coins

    Gold does not oxidize, except for an extremely thin film invisible to the naked eye, is not attacked by any acid except Aqua Regia (described on page 21), and does not combine with sulfur. Because pure gold is never present in coins, some minor discoloration sometimes occur with gold. The following methods can be used for cleaning gold coins:

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  • Refining Gold with Sulphuric Acid

     · Parting Gold-Silver Alloy with Sulphuric Acid. Alloys of 10 grains of gold, assaying 9992, were taken, and alloyed with 10, 15, 20 grains of fine silver respectively. Each alloy was rolled out in the same manner as was adoped for the nitric acid parting; 20cc of strong sulphuric, 92 per cent., acid was used in each case, and the cornets were ...

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  • Cleaning Up Mining Waste

    Cleaning Up Mining Waste Political Economy Research Center Stuart Buck and Da vid Gerard Research Study 01-1 • November 2001 4! Acid drainage, "water containing acidity, iron, manganese, aluminum," and possibly "iron hydroxide and sulfuric acid,"12 can enter water supplies according to the Environmental Protection

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  • How to Refine Gold by the Acid Method

    First immerse the end of the stirring rod in the acid. Remove it and touch that end to a paper towel to make a wet spot. Put a drop of gold detection liquid on the wet spot on the paper towel. If any gold is still dissolved in the acid, the wet spot will turn a purple-black or a purple-brown.

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  • Sulphuric Acid Parting of Gold & Silver

     · Washing and Melting the Gold Residue. The residue in the dissolving pot, if the amount of base metals present is not large, is then boiled twice more with fresh concentrated sulphuric acid added hot, after which the gold residue is hard and heavy and rapidly subsides to the bottom, and the liquors are ladled into the precipitating vat.

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  • Sulphuric Acid Parting of Gold & Silver

     · Washing and Melting the Gold Residue. The residue in the dissolving pot, if the amount of base metals present is not large, is then boiled twice more with fresh concentrated sulphuric acid added hot, after which the gold residue is hard and …

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  • Gold With sulfuric acid

     · Eletroplating gold

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  • Cleaning Gold

     · Well, it came in the mail today and for reasons beyond comprehension he decided to clean it. The silver mount I guess melted in the acid, it looks I think much less interesting and the weight is down to 26.2g from it''s natural state at 29.32 a little of that lost fine gold.

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  • Gold cleaning methods for electrochemical detection ...

    This work investigates methods for obtaining reliably clean gold film surfaces. Nine gold cleaning methods are investigated here: UV ozone photoreactor; potassium hydroxide–hydrogen peroxide; potassium hydroxide potential sweep; sulfuric acid hydrogen peroxide; sulfuric acid potential cycling; hydrochloric acid potential cycling; dimethylamine borane reducing agent solutions at 25 and 65 ...

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  • Amino acids key to new gold leaching process

     · Being an alkaline compound, he says it is well suited to extracting gold in alkaline ores such as dolomite, unlike sulphuric acid. Ores treated in this way require no milling, a …

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  • REFINING-RECOVERY AND REFINING WITH JUST NITRIC ACID ...

    stir the mix daily and just add more sulfuric acid after you pour off the mixed acid. this procedure will work with the following gold bearing materials. ... now using just water take all the paint filters and rinse the gold out of the filters into a clean contaner. let it set until the gold …

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  • Pickling Notes

    Sulfuric acid however is dangerous to store, handle and mix up. It also wants to concentrate to a 49% solution, which means it evaporates until it reaches this dangerously corrosive proportion. With the introduction of safety and (maybe litigation) pressures jewelers began to turn to dry salts which dissociate to form constant dilutions of acid.

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  • The 4 Most Dangerous Acids in the World

     · Piranha Solution . Piranha solution, or Caro''s acid (H 2 SO 5), is like a voracious chemical version of the carnivorous fish.Except instead of eating small animals, this mixture of sulfuric acid (H 2 SO 4) and hydrogen peroxide (H 2 O 2) devours pretty much any organic molecule it encounters.Today, this acid finds its main use in the electronics industry.

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  • The Environmental Disaster That is the Gold Industry ...

     · Exposing the deep earth to air and water also causes chemical reactions that produce sulfuric acid, which can leak into drainage systems. Air quality is also compromised by gold …

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  • Cleaning/leaching a plating tank

     · We are replacing a lead lined tank with a new 2330 gallon tank that will contain a solution of Sulfuric Acid (14% by vol of 93% pure), Sodium Dichromate (4.5oz per gal) and 33 lbs of aluminum. Does your experience with PP tanks require a cleaning or leaching of the tank to prevent contamination of any sort from the PP tank?

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  • Aqua regia

    Aqua regia dissolves gold, although neither constituent acid will do so alone.Nitric acid is a powerful oxidizer, which will actually dissolve a virtually undetectable amount of gold, forming gold ions (Au 3+).The hydrochloric acid provides a ready supply of chloride ions (Cl −), which react with the gold ions to produce tetrachloroaurate(III) anions, also in solution.

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  • Gold recovery process from Ceramic CPU''s

    Note: Don''t forget to examine the ceramic pieces for missed out gold (see video) Stir the solution and ice cubes well with a glass stirring rod and slowly add 10-15 ml of concentrated Sulfuric acid. Do remember, concentrated Sulfuric acid reacts very vigorously upon contact with water, so any addition should be done slowly and by the drop.

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  • 9:1 Piranha Solution | Stanford Nanofabrication Facility

    9:1 Piranha Solution. Preferred Short Name: 9:1 Piranha. Chemical Formula: 9:1 H 2 SO 4 :H 2 O 2. Full Chemical Name (for In-Use Hazardous Chemicals card): 9:1 Sulfuric Acid : Hydrogen Peroxide. Items per page. 5 10 20 40 50 60 - All -.

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  • Gold Recovery Correctly : 12 Steps

    Gold fingers are typically found on PCI cards, ISA cards, or on Memory sims/dimms/etc. They create the corrosion free connection between the computer and the expansion card. This process can also be used to recover gold from CPU such as Pentium Pro, or Cyrix or older 486 and lower generation chips.

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  • Chemical Cleaning of Coins

    The following compounds involved in chemical cleaning of coins are capable of reacting with coinage metals: • Acids (Hydrochloric acid, Sulfuric acid, Nitric acid, Vinegar, Lemon and Tomato juices, etc.) CAUTION: DILUTION OF SULFURIC ACID MUST ALWAYS BE DONE BY POURING ACID INTO WATER IN A FINE STREAM, NEVER by pouring water into concentrated ...

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  • Chapter 1.10

    These will not etch gold, etc. Phosphoric acid at 60ºC Sodium hydroxide (10% solution) - 2 - ... To clean (purify), bubble air through mercury, filter and vacuum distill. ... Always add peroxide to sulfuric acid, never vice versa! This is a self-heating solution. - 8 -

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  • A Method for Leaching or Dissolving Gold from Ores or ...

    content was measured by reacting it with sulfuric acid and hydrogen peroxide and measuring the oxygen evolved by gas analysis using a Lunge burette.14 Reducing reactant for precipitating gold such as iron (II) sulfate and oxalic acid were all ACS grade and both purchased from Fisher Scientific.

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  • Acid-Resistant Aprons | McMaster-Carr

    Made of flexible PVC, these aprons hold up against acids and alkalies such as sulfuric acid and sodium hydroxide. They are water resistant, and have a tie in the back.. Bib aprons with reinforced straps and ties have a second layer of PVC on the neck strap and waist ties for added durability.. Bib aprons with a reinforced stomach have an extra layer of PVC sewn over the stomach for added ...

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  • How to Use Bleach on Gold Ore to Remove Gold | Sciencing

     · Pour the acid-and-bleach mixture into the plastic bowl with the ore grains and stir. Allow four hours for the gold to dissolve, stirring every 20 minutes. The chlorine reacts with the gold inside the ore to form gold chloride. Filter the ore and bleach solution to …

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  • How to Make a Gold Test Acid Solution | eHow

     · Professional jewelers and jewelry appraisers often use gold acid tests to determine gold jewelry''s value. Different acids react differently when dripped on specific base metals, allowing you to tell how pure your gold is. Since gold is so soft, most gold jewelry today is made of an alloy of some kind.

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  • HDPE Chemical Resistance Guide

    Methyl alcohol () S S Sulfuric acid S S Methyl ethyl ketone () U U Sulfuric-nitric S U. HDPE Chemical Resistance Guide Legend: S = Satisfactory O = Some attack U = Unsatisfactory 4 of 5 Reagent (21" C) (60" C) Reagent (21" C) (60" C) Pine oil Plating solutions Brass Cadmium Chromium Copper Gold Indium Lead Nickel Rhodium Silver ...

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  • How to Test Gold With Muriatic Acid | eHow

    Drop a very small amount of muriatic acid (hydrochloric acid) onto the gold, using a medicine dropper. Take extra care not to spill or allow any acid to come into contact with your skin to avoid injury. Muriatic acid is a very strong corrosive chemical that can damage surfaces; avoid …

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  • How to Test Gold

    This is not pure gold. Step 4: Purchase hydrochloric acid or sulfuric acid, rubber gloves, and protective eyewear from a hardware store. Use something like a small piece of glass to drop a very small amount of acid onto the gold. If the gold begins to dissolve, then there is some other type of metal mixed with the gold and it is not pure.

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  • Krishna Saraswa

    • "Piranha" is a heated, boiling mixture of concentrated sulfuric acid (H 2SO 4) and ~ 30% hydrogen peroxide (H 2O 2). • This is a strongly oxidizing acid mixture that is used for removal ... belonging to the groups "Clean" -> "Semi-Clean" -> "Gold-Contaminated", but generally not the reverse (exceptions listed ...

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  • Piranha Clean (Sulfuric Acid and Hydrogen Peroxide Mix)

    2.1.4 Fill the container ¾ full with 96% sulfuric acid (make sure to leave some space at the top of the container – so if you are using a 1000 mL beaker, for example, fill to the 750 mL mark with 96% sulfuric acid). 2.1.5 Cap the sulfuric acid bottle and put it away. 2.1.6 Bring the hydrogen peroxide bottle, and pour in 1/3 the volume used ...

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  • Gold cleaning methods for electrochemical detection ...

     · Gold samples spent 10 min in this treatment before being rinsed with Milli-Q. Abbreviated "H 2 SO 4 + H 2 O 2 " in the results. 3.5. Sulfuric acid potential cyclingCycling the electrode potential in a weak sulfuric acid solution until a stable CV scan is achieved is a very common electrochemical cleaning technique, .

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