A method for extracting molybdenum and nickel and enriching precious metals from nickel-molybdenum ore

Abstract

The invention provides a method for extracting molybdenum and nickel and enriching precious metals from nickel and molybdenum ores. The method comprises the steps of (1) carrying out oxidized desulfurization and roasting; (2) smelting at high temperature to separate nickel and molybdenum: heating to 1250-1550 DEG C to enable the mixed furnace charge to be fused, and then, preserving the heat for 20-40min; (3) leaching and extracting the molybdenum for the first time; (4) leaching and extracting the molybdenum for the second time. The method provided by the invention is only used for removing sulfur in the nickel and molybdenum ores to be below 10%, so that the long roasting process is avoided, SO2 in the obtained smoke is high in concentration and can be directly used for preparing acids, meanwhile, the roasting time is greatly shortened, the production efficiency is remarkably increased, and the operation difficulty is lowered. The molybdenum can be converted into sodium molybdate and reserved in molten alkaline slag through adding sodium carbonate into the roasted clinker and melting the sodium carbonate under an alkaline condition, while the nickel is produced in an iced nickel or ferronickel way, so that the efficient separation of the nickel and the molybdenum is realized. The sodium carbonate is added in a melting process, so that the melting point and viscosity of the molten slag are reduced, and the iced nickel or ferronickel can be favorably settled and enriched.

Description

technical field [0001] The invention belongs to the technical field of mineral extraction metallurgy, and relates to a method for efficiently extracting molybdenum and nickel from nickel-molybdenum ore and enriching precious metals. Background technique [0002] There are a large number of nickel-molybdenum deposits in my country's Guizhou Province and Xiangxi, Hunan and other regions. This kind of mineral is a polymetallic associated sulfide ore. Due to the different ore-forming conditions and the location of the region, the associated valuable elements are also different, but it is mainly molybdenum and nickel. A small amount of tungsten, vanadium and gold, silver, platinum, palladium and other precious metals are usually called nickel-molybdenum ore or molybdenum-nickel ore. This kind of nickel-molybdenum ore containing molybdenum and nickel has a wide distribution area and large reserves, and the grades of molybdenum and nickel are relatively high (compared with molybde...

AI Technical Summary

Problems solved by technology

[0004] The common pyrotechnic process for processing nickel-molybdenum ore is: crush nickel-molybdenum ore, oxidize and roast it for desulfurization, then add lime and coke to the roasted clinker, and directly heat it in a small blast furnace or an electric furnace at a temperature higher than 1500°C. Reduction refinement is made into coarse nickel-molybdenum alloy. The obtained nickel-molybdenum alloy contains 15-20% molybdenum, 8-20% nickel, phosphorus > 0.6%, and sulfur > 1%. Although this method has the advantages of simple equipment and process, and large raw material processing capacity , low production cost, the yield of molybdenum and nickel can basically meet the requirements, etc., but its disadvantages are that the smelting product is a molybdenum-nickel alloy eutectic, molybdenum and nickel cannot be separated, and the harmful impurities in the alloy phosphorus and The sulfur content is high and the use is limited. Subsequent molybdenum and nickel separation and impurity removal treatment must be carried out to obtain qualified molybdenum and nickel products, which will eventually lead to a decrease in the yield of molybdenum and nickel and an increase in cost

The shortcomings of this method to extract molybdenum from nickel-molybdenum ore are that the yield of molybdenum is not high, the production efficiency is low, and nickel cannot be recovered in the form of nickel products at the same time, and the overall benefit is poor.

The invention claims that the yield of molybdenum is 90%, and the yield of nickel is 93%. Although the invention has got rid of the roasting process and eliminated the pollution to the quality of the air environment, the comprehensive utilization is better, and the recovery rate of molybdenum and nickel is also higher. However, a large amount of sulfuric acid and chemical raw materials need to be used, more equipment is required and anti-corrosion is required, the process is longer and the treatment capacity is small, and the waste water containing nitrate is not easy to treat.