It belongs to renewable sources of raw materials are cobalt super alloy containing Co50 ~ 60% and of Ni10 ~ 30%, the magnetic alloy containing the Co8 ~ 24 containing Co5 ~ 12% of the high-speed cutting alloys, catalysts for the petrochemical industry as well as other Scraps with high cobalt content, etc. Not long ago, foreign countries also believed that the production of cobalt in recycled raw materials was unprofitable. Later, this view changed. As early as 1979, nearly 2,000 tons of cobalt were produced from recycled raw materials.
The American example is the best sign in this regard. The United States is the basic user of cobalt consumption. In 1980, the country consumed 7,260 tons of cobalt, of which 544 tons were produced from recycled materials.
In the (former) Soviet Union, cobalt- nickel scrap was processed in a modern nickel enterprise by hydrometallurgical methods .
Co-processing of raw and recycled raw materials
In the process of nickel oxide ore treatment, copper is leached after secondary sulphuric acid chlorination roasting, and the obtained solution contains (g/dm 3 ): Cu 10 ～ 20, Co 0.3 ～ 0.7, Ni 4 ～ 8, Fe1 ~ 2. When acidified to a sulfuric acid content of 50 to 60 g / decimeter 3 , it can be used to dissolve metal scrap with a high cobalt content. Component (%) of waste: Co10-17, Ni23-51, Fe32-57, Cu0.1-0.3.
In an oxidizing environment (air bubbling), the following reactions occur at a temperature of 65 to 75 °C:
CuSO 4 +Me=Cu+MeSO 4 (1)
H 2 SO 4 +Me=MeSO 4 +H 2 O (2)
2FeSO 4 +H 2 SO 4 +1/2 O 2 =Fe(SO 4 ) 3 +H 2 O (3)
Fe(SO 4 ) 3 +Me=2FeSO 4 +MeSO 4 (4)
In the formula, Me represents nickel, cobalt and iron .
When the residual acidity of the H 2 SO 4 solution is 3 to 4 g/dm 3 , the process is finished. The resulting solution contained (g/dm 3 ): Co 5-8, Ni 12-20, Fe 25-35, Cu 6-12. Enter the storage container where it is cleaned of iron and copper. The purification can be carried out together with the solution for treating the raw material, or separately. Iron is precipitated as a trivalent basic salt, and copper is precipitated as a replacement slag or as an alkali carbonate CuCO 3 ·Cu(OH) 2 . The recovery of nickel and cobalt in the solution is 90%.
The insoluble residue remaining after the scrapped tungsten- molybdenum product is sintered is sent from a company that produces cemented carbide. The chemical composition is (%): Co21-27, Ni2~3, Cu2~3, Fe3.5-6.0, Mo1~2, W2~4, Ti1~5, wherein cobalt is a high-valent oxide CoO·Co 2 O 3 And an oxide of the CoO·MeO type.
At a temperature of 65 to 75 ° C, in the case of ordinary sulfuric acid leaching of a similar product, 14 to 18 hours of sulfur dioxide bubbles are introduced into the solution, and only 60 to 70% of the cobalt in the solution can be recovered. The pre-reduction roasting of these wastes can increase the recovery in the solution to 96-98%.
As the initial research and subsequent practice have proved, high temperature (90 ~ 95 ° C) leaching can be obtained. When sulfur dioxide is bubbled in 6 to 7 hours, and the final concentration of sulfuric acid is 30 to 35 g/dm 3 , 90% or more of Co enters the solution.
The composition of the obtained solution is (g/dm 3 ): Co40-60, Cu4-6, Fe4-6, and impurity removal is required; associated metals--- chromium , titanium , tungsten, molybdenum remain in the leached slag, in tungsten In the enterprises of the molybdenum industry, they can be handled reasonably.
The waste containing nickel, chromium, tungsten and molybdenum is the sludge obtained after electrochemical treatment of the nickel alloy, and its approximate composition is (%): Ni17.0, Co3.7, Mo1.2, W1.6, C2.4 Below NaC150. There are also a small number (about 0.5 to 1.5%) of iron, aluminum , vanadium , titanium and silicon. This sludge can get 5,000 to 7,000 tons in one year.
(Former) The Institute of Metallurgy of the Ural Science Center of the USSR Academy of Sciences recommended on the basis of its own research to leaching sludge in sulfuric acid solution. The optimum leaching conditions were: pH = 2.9 to 3.0, temperature 50 ° C, and time 2 hours. Under these conditions, the recovery of nickel and cobalt in the solution is 94 to 96% (total), and the tungsten and molybdenum remaining in the insoluble residue are still 92 to 95%. The residue can be treated according to known processes, which contain 7 to 10% Mo and 10 to 14% W. A solution containing Ni 10 to 14 g/dm 3 and Co 2.5 to 3.5 g/dm 3 can be treated as appropriate by a hydration process, followed by cobalt oxide or cobalt.
cat piston pump,caterpillar piston pump,cat hydraulic piston pump,cat excavator piston pump
Xuzhou MMT Machinery Co., Ltd. , https://www.mmtspareparts.com