As the market for nickel-metal and platinum group metals demand urgent, nickel and platinum metals prices have been high, prompting concern copper-nickel ore beneficiation, and therefore put more funding for this research.
The Norrsk Nickel Metallurgical Company Tarnahsk Concentrator replaces the past positive-priority flotation process with a preferential mixing-separation flotation process for dense copper-rich nickel ore to increase the recovery of useful components. Recently, an improved priority-mixing-separation flotation process, namely the first coarse grinding (58%-0.045mm instead of the previous 83%-0.045mm), has been used to reduce the number of grinding and grading equipment , and then float copper first. then flotation of copper, nickel and pyrrhotite, as much as possible to the crude recovery of useful minerals concentrate, gangue minerals discarded, and then separating the mixed flotation concentrate. The recovery rate of copper and nickel in the new process copper concentrate and nickel concentrate is increased by 3% to 4%.
Copper concentrates, nickel concentrates and pyrrhotite concentrates are obtained at the Norilsk Nickel Tarnaschke concentrator using a positive priority flotation process. In order to fully recover copper, sodium sulfite or sodium hydrogen sulfite is added to the copper-nickel ore copper flotation circuit to increase the recovery rate of copper, but at the same time, the concentration of thiosulfate ions in the nickel flotation feed is increased, thereby inhibiting nickel. Flotation of minerals. Studies have shown that increasing the amount of collector in the nickel flotation circuit, adding sulfuric acid to decompose thiosulfate ions or adding hydrogen peroxide regulator can prevent the inhibition of nickel minerals by thiosulfate ions.
Norilsk's Tarnahsk concentrator uses positive-preferred flotation to treat copper-nickel-containing pyrite ore. In order to ensure that the concentrator obtains better flotation indicators, the concentrator's return water pH should be stable at 7.5-8.5. The thiosulfate ion and organic flotation reagent should not exceed the allowable range.
The Norilsk Concentrator uses a mixed flotation scheme instead of the original preferred flotation scheme. That is, the raw ore is coarsely ground to 40%~45%-0.045mm, and the first stage copper-nickel mixed flotation is carried out according to the specially formulated process and pharmaceutical system to separate the copper-nickel mixed concentrate containing pyrrhotite. After the concentrate is further ground to 80%-85%-0.045mm, the pyrrhotite is separated from the copper sulfide and nickel sulfide mineral by flotation method, that is, the magnetic yellow iron is inhibited by dimethyldithiocarbamate. Mineral, flotation of copper sulfide and nickel sulfide minerals. The obtained copper-nickel mixed concentrate is directly treated by metallurgical methods. The recovery rate of nickel in the new process is increased by 11%, the yield of mixed concentrate is reduced to 1/4, and the cost of concentrate smelting is greatly reduced.
In the first mixed-separation vehicle of the Norilsk Concentrator, the re-election-mixing flotation-separation flotation combined process was used to treat the Norilsk-1 deposit-disseminated ore, the Tanah's crater-rich dip-coated ore and the Communist Youth League. Mine ore 3 kinds of ore. The total character of the ore is high gangue content: from 85% of copper ore to 95% to 96% of disseminated ore. It is an important task for the ore dressing worker to reduce the amount of non-metallic minerals entering it to improve the quality of the mixed concentrate and to improve the quality of the separated concentrate entering the downstream metallurgical plant. In the past 3 years, Norilsk Mining and Metallurgy Company has completed a large number of laboratory tests, selecting the most effective inhibitor for the mixed flotation circuit of the ore and copper ore - ΜЗЦ-2, which is a modified fiber. Alkyl ester. The test results show that the recovery rate of the obtained mixed concentrate nickel and platinum group elements is increased by 2.5% to 8.0%, and the sulfide content in the mixed concentrate is increased by 5% to 8.0%.
Since the production capacity of the Tarnahsk concentrator has been able to handle all the dense and massive sulphide ore that can be mined in the Tarnakhsk mine in recent years, the excess production capacity of the Norilsk concentrator can be used to separate Handling disseminated ore and copper ore that were simultaneously mined in the past, as well as processing pyrrhotite concentrates that have been stored in the past. In addition to the conventional flotation process, the dyed ore is also subjected to flash flotation and re-election of precious metals from flotation tailings; a positive-priority flotation process is used in copper ore processing; The iron ore concentrate is pre-selected with precious metals and scrubbed with ore. The selected nickel-pyrite concentrate is sent to the nickel smelter together with the nickel concentrate separated from the disseminated ore and rich ore to supplement the shortage of raw materials in the nickel smelter. The shortage of raw materials in the nickel smelter is due to the rich ore. The Norilsk Concentrator was replaced by the Tarnahesk Concentrator and a portion of the nickel concentrate was sent to the Najazhinsk Smelter for disposal. Therefore, from 2000 to 2001, the Norilsk Concentrator used a new combined process of various beneficiation methods to separately treat leaner, more complex ore-contaminated ore, copper ore and stored pyrrhotite concentrates. . The beneficiation process can achieve higher technical and economic indicators, and can also produce other by-products.
The study on the composition of copper-nickel ore in Norilsk Concentrator shows that the content of platinum group metals and the content of non-ferrous metals (copper and nickel) vary with the type of ore. The copper and nickel rich dense ore platinum group metals have a low grade, while the copper and nickel grades have a low content of platinum group metals with high content (containing 0.015% to 0.15% Ni, <0.15% Cu and 9g/t platinum group metals). ). Moreover, the floatability of platinum group metal minerals in ore is relatively low, and it is more reasonable to use re-election (Nielsen centrifugal concentrator)-flotation treatment. The grades of platinum group metals for re-election concentrates and flotation concentrates were 450 g/t and 85 g/t, respectively. The total concentrate platinum group metal recovery rate is 75% to 80%.
Norilsk Nickel Mining and Metallurgy Company's new resources: 1 low sulphide ore, copper and nickel grade is very low (0.1% ~ 0.2%), but the platinum group metal content of 6 ~ lOg / t. It was not treated in the past, but it can be treated by re-election (Nielsen centrifugal concentrator)-flotation method or flotation method (with disseminated ore process). The content of platinum group metal in concentrate is 136g/t, and the recovery rate is 74%. The ore may be added to the standard disseminated ore in an amount of 2% to 3%. 2 Off-balanced ore and long-term storage of impregnated ore, the material nature is complex, there is no uniform process to deal with it. One of them is treated by re-election (Nielsen centrifugal concentrator)-flotation method. 3 The pyrrhotite and magnetite concentrate storage materials are recovered from the platinum group metal by a Nielsen centrifugal concentrator.
An urgent issue for Norilsk Mining and Metallurgy is to develop a pyrrhotite concentrate for processing. That is, the feed material is delimed by a cyclone, and the grit is sorted by a Nielsen centrifugal concentrator, and the concentrate is shaken and selected. The concentrate contains 1.77% Cu, 2.53% Ni, 300-700 g/t Pt and 10-30 g/t Au. The yield was 1%, and the copper and nickel recovery rates were 82% to 86% and 80% to 84%, respectively. The concentrate is re-selected for processing in the metallurgical workshop.
Due to the sharp increase in demand for platinum group metals in the international market in recent years. Promote the recovery of platinum from the Norilsk copper-nickel concentrator in Russia. First, the recovery of platinum metal from the tailings of the plant was studied. The old tailings of the concentrator were magnetically selected to obtain a magnetite concentrate containing about 20 g/t of platinum group metal, and then the magnetite concentrate was selected by a Nielsen centrifugal re-election machine and a shaker. The concentrate contains 5~7kg/t precious metal and is sent to the smelting plant for treatment.
The magnetic pyrite concentrate of Norilsk Nickel Mining and Metallurgy Co., Ltd. contains about 2% nickel. The pyrrhotite concentrate, the iron-containing additive (iron concentrate or converter slag) and the reducing agent ( coal ) are subjected to reduction roasting and weak magnetic separation. The test results show that when the calcination temperature is 900 ° C and the calcination time is 30 min, the ratio of pyrrhotite concentrate to magnetite concentrate is 2..1, which contains Ni 6.18%, Cu 0.67%, Co 0.288%, Fe 71.4%. And 9.9% of the magnetic products, the recovery rate of entering the magnetic product was Ni 85.1%, Cu 16.6%, Co 82.6%, Fe 33.4%, and the yield of magnetic concentrate was 23.9%.
The use of magnetite as an iron-containing additive for the reduction roasting magnetic separation of low-nickel pyrrhotite concentrates. The results show that during the roasting process, the optimum mass ratio of low-nickel pyrrhotite concentrate to magnetite concentrate is 4..1, and the optimum calcination temperature is 800-800 °C. Under the optimal calcination conditions using coal as a reducing agent, the nickel grade of the magnetic separation concentrate is 2.37% to 2.7%, and the nickel recovery rate is 70.3% to 71.1%. When the producer gas is used as the reducing agent, the nickel grade of the magnetic separation concentrate is 2.84% to 3.64%, and the nickel recovery rate is 66.6% to 71.9%. The magnetic separation concentrate can be treated by pyrometallurgy, and the sulfide product captures 90% of the sulfur in the raw material and enters the magnetic separation tailings.Based on metallic frames, Canway medical tents are specially designed as mobile hospitals in emergency situations when equipped with medical necessary accessories. Robust and sturdy structures are the guarantee for the stability. Covered with durable and waterproof materials, the medical tents can shelter patients and medical staff from heavy rain and sun. Different inner liners can be applied for different emergency situations by adding curtains or side walls. Air beds and sleeping mats can quickly be inflated with an electric pump or a hand pump for the sick people when time is critical. In extreme weather, air conditioning system is a good choice for the medical tents to keep a comfortable environment. According to different medical needs, these tents can be customized to different sizes and functions, such as operating rooms, intensive care units, wards and so on. Different medical zones can also be connected with each other by zippers or velcro just like a real hospital, which is convenient for medical workers.
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