1.Platinum recovery methods in nitric acid plants
Platinum, palladium, rhodium ternary alloy catalyst network is used in the production of Nitric acid. Precious metals depleted in the production mostly deposit in the ashes of oxidation oven. Researched by Kunming Institute of Precious Metals and Taiyuan Chemical Fertilizer Plant, and the process flow are as follows: Ashes → reducing smelting iron trap→ Oxide melting → Acid leaching → Calcined residue → Wet purification → Platinum palladium rhodium ternary alloy powder. Straight yield of Pt, Pb, Rh is 83%; overall yield is 98% and product purity of 99.9%. Old platinum recovery process is simple, and waste network will be changed into net after dissolution, purification, reduction and combining silk. Its recovery rate>99%.
2.Platinum recovery methods in glass industry
Kunming Institute of Precious Metals proposed, Pt, Rh, Au alloy waste water is dissolved with aqua regia, then in time for denitrification to sodium, then restore the separation gold with hydrogen peroxide, then ion exchange getting rid of impurities, consequently hydrazine hydrate to restore a pure Pt, Rh. Platinum and rhodium results in 99% purity, recovery rate of 99%. Institute of recycled material put forward the technology of recovering platinum and rhodium from waste firebrick and glass waste with the method of "dolomite sintering a mixture of soda ash". Dissolve the waste firebrick with aqua regia after ball mill, liquating, water crushing, acid soluble, filtering and residue, then in time for denitrification and ion exchange; hydrazine hydrate to restore platinum and rhodium. Overall yield of platinum and rhodium>99% and product purity is 99.95%. Combining with production practice of many years, the institute put forward combining method of beneficiation and smelt metal to recover platinum and rhodium in waste firebrick, which reduces cost, shortens process and gets very good effects.
3.Recover platinum, palladium from spent catalyst
First, Law of dissolution of Precious metal, Kunming Institute of Precious Metals and Shanghai Petrochemical Plant use high temperature baking, hydrochloric acid increases oxidative leaching, zinc replacement, hydrochloric acid plus antioxidants dissolved, solid ammonium chloride Shen platinum, a pure platinum calcination, platinum purity of product is 99.9%, recovery rate is 97.8%. And this has applied for China’s patents.
Second, materials recycling institute in cooperation with the five nuclear industry to adopt the "fusion" leaching, ion exchange adsorption of Pt (or Pd), platinum recovery rate of> 98%. Palladium yield> 97%. Product Purity> 99.95%. China has applied for patents, and the use of a few factories.
Third, the use of renewable materials and Yangzi Petrochemical Company Institute study of palladium from spent catalyst in the recovery of palladium carbon. Spent catalyst by burning carbon, chloride leaching, ammonia complex, acid purification, the purity of the final hydrazine hydrate is reduction by> 99.95% sponge palladium complex in a small amount of liquid residue, such as palladium recovery by resin adsorption. The recovery rate of palladium is> 98%. And this has applied for patents in China
4.Scrap platinum, rhenium catalyst recovery
One is that cooperated by recycling of materials research institute with Changling refinery, a method turns out that to take "all dissolved Law" leaching, ion exchange adsorption of Pt, this is called Pt precipitant separation method. Platinum recovery rate is>98% and rhenium recovery rate is>93% and their purity rates both >99.95%. The raffinate aluminum sulfate can be used as catalyst support production material.
The other is recycling of platinum and rhenium by extraction of the waste catalyst which is by cooperation of Tsinghua University and Beijing rare precious metals plant. Spent catalyst with 40% sulfuric acid dissolved and dissolved with 40% liquid sulfone Diisobutyl to extract rhenium, then recover rhenium by stripping liquid potassium. In addition, acid-insoluble residue burning remove carbon, acid-soluble platinum Baptist, Baptist 40% Platinum solution by diisobutyl sulfoxide extraction of platinum, anti-stripping solution to restore the platinum. Platinum extraction rate is>99%, back-extraction rate>99%, platinum direct yield>97%, the product platinum purity is 99.9%; Rhenium extraction rate is>99%, anti-identification rate>99%.
5.Separation and Purification of platinum and rhodium alloy
Kunming Institute of Precious Metals has stated, platinum and rhodium alloy aluminum alloy "broken, and diluted hydrochloric acid leaching of aluminum, platinum and rhodium have been fine powder, hydrochloric acid plus antioxidants dissolved solution with Trialkyl oxide platinum and rhodium extraction, ion exchange purification of rhodium. rhodium purity is 99.99%, rhodium recovery rate 92~94%. Also it has applied for patents in China. Besides, Factory 208 in Chengdu introduces platinum and rhodium separation equipment from Japan. Yield of 98.5% platinum, rhodium yield 95%, platinum and rhodium purity over>99.95.
6.Purification osmium peroxides from Iridium alloy waste
The branch of original material recycling parent company in China, East China Branch Company adopts combustion oxygen to separate osmium from iridium, alkali lye absorbs osmium oxide, sodium sulfide precipitation, with the exception of sulfur osmium get rough osmium, and then oxidation, absorption of hydrochloric acid solution, ammonium chloride precipitation, hydrogen reduction, take pure osmium powder, osmium recovery rate>98%. This method is suitable for waste with osmium containing of 3%~8%.
7.Recycling of ruthenium in nib grinding waste
East China branch proposed flotation recovery of nib grinding waste containing 0.4%~1% of ruthenium. Agents for the flotation of sodium oleate, 2 # oil as the foaming agent, an acidic medium. Obtained concentrate contains ruthenium>5%, tailings contains ruthenium<0.2%, ruthenium recovery rate>90%.
8.Recycling of palladium and copper from waste catalyst residue
First, recycling of materials research institute using the method of Hcl-H2O2two-section countercurrent leaching with xanthate deposition and separation of palladium and copper and recover palladium and copper from waste catalyst residue with Pd0.8%, Cu26.2%. Recovery of Pd>98%, Cu>95% .
Second, Shenyang Institute of Mining and leaching with dilute Hcl copper, iron replacement of copper, leaching slag oxidation roasting, dilute aqua regia leach, zinc replacement, coarse palladium dichloride ammonia Purification, and palladium purity of 99.99%. Recovery rate>98%, copper yield 92%.