1. Nickel ore and minerals
In the modern technical and economic conditions, the process can be carried out on an industrial scale, extraction of metals or raw product called ore mineral aggregates, mineral can human use, called the useful minerals. If the content is not too low, it is not suitable for processing on an industrial scale. It is called gangue, and the gangue is waste rock. Therefore, the ore consists of two parts, namely useful minerals and gangue.
The content of nickel in the mantle is estimated to be about 0.02%, which is equivalent to twice the total of copper , lead and zinc . However, there are not many nickel deposits that can be mined. Due to the low mined ore from the mine nickel grades, most of them are subject to beneficiation of nickel concentrate to get used to smelt.
Nickel is generally divided into three categories: sulfide nickel ore, nickel ore and arsenide. The nickel-containing minerals of nickel arsenide are red nickel (NiAs), arsenic nickel (NiAs 2 ) and arsenic nickel (NiAsS). These minerals are only produced in North Africa and have a small amount of output. Nickel is limited to individual countries. About 70% of the world's nickel production is produced from nickel sulfide ore and 30% from nickel oxide ore. In China, nickel sulphide ore accounts for a larger proportion.
Nickel is the last metal element in the transition metal iron composition of the periodic table. It evolves from oxophilic to thiophilic, so nickel and cobalt are mainly sulfide produced in nature, in all pyrrhotite (Fe 7 S 8 ). Nickel has an advantage, while in pyrite (FeS 2 ), the cobalt content is higher.
There are more than 60 kinds of known nickel minerals. The industrial value mainly includes the following six kinds of sulfide ore (including Ni 1.0% - 2.5%) and three kinds of oxidized ore (including Ni 0.5% - 1.5%), as follows The table shows.
Mineral name | Chemical formula | Mineral name | Chemical formula |
Nickel pyrite | ( Fe,Ni ) 9 S 8 | Cobalt nickel pyrite | ( Ni,Co ) 3 S 4 |
Nickel-containing pyrrhotite | ( Ni , Fe ) 7 S 8 | Dark nickel serpentine (Aqueous nickel magnesium silicon | 4 ( Ni,Mg ) 4 . 3SiO 2 . 6H 2 O |
Needle sulfur nickel ore | |||
Purple sulfur nickel iron ore | ( Fe,Ni ) 2 S 4 | Silicon magnesium nickel ore | H 2 ( Ni,Mg ) SiO 4 . xH 2 O |
Hui iron nickel ore | 3NiS . FeS 2 | Nickel-containing laterite ore | ( Fe,Ni ) O( OH). nH 2 O |
Nickel sulphide ore usually contains copper mainly in the form of chalcopyrite (CuFeS 2 ), so nickel sulphide ore is often called copper-nickel sulphide ore, and sulphide ore contains cobalt (the amount is 3%--4 of the amount of nickel). %) and a platinum group metal. The average nickel content in copper-nickel sulfide ore varies widely, from a few hundred thousandths to 5%--7% or more. Copper-nickel sulfide ore can be divided into two categories: dense lump ore and dip-dyed mined ore. From the perspective of process technology, this classification facilitates the next step of processing various types of ore. The nickel-depleted leached ore is directly disposed of in the beneficiation workshop, while the dense ore containing nickel is sent directly to the smelting or magnetic separation. The characteristics of copper-nickel sulfide ore are that the milk is hard and difficult to break, and the second is that it does not burst when heated. The reason is that the sulfide in the ore is mainly magnetic pyrite .
2. Nickel sulfide concentrate and copper sulfide nickel concentrate
At present, most of China's nickel mines are produced by copper sulfide nickel ore. The content of valuable metals in copper-nickel ore is very low, and the milk is changed. Such ore is directly consumed in the smelting of milk, and it is economically uneconomical. Therefore, after the ore is mined, it is necessary to carry out ore-concentration, and a large number of gangues are subjected to ore dressing, and then a higher amount of valence metal is obtained. The concentrate then enters the metallurgical furnace to produce metals such as copper and nickel.
For copper-nickel ore containing more than 7% nickel, it can be directly sent to smelting; less than 3% should be subjected to beneficiation and enrichment. The impregnated ore concentrate generally obtains a nickel sulfide concentrate or a copper sulfide nickel concentrate with a preferential or integrated float. Comprehensive flotation is suitable for the treatment of ore and small-scale enterprises with high nickel content. At this time, copper and nickel are selected together to obtain copper-nickel concentrate, and there is no need to establish another copper plant to separately smelt copper concentrate. However, for enterprises with high copper content, low nickel content and large production scale, it is easy to float economically and technically. The copper sulfide concentrate obtained by preferential flotation is relatively fusible, and the chalcopyrite is more easily floated than the pyrite of nickel pyrite, and the chalcopyrite in the ore is present as individual grains. [next]
China's Jilin Nickel Metallurgical Company's beneficiation uses preferential flotation. Jinchuan Company adopts integrated flotation and conducts beneficiation according to two sets of technologies: lean mine series and rich mine series.
The lean ore dressing process includes three-stage ball milling and two-stage flotation. The second estimate is that the second section of the ball mill grinds the ore to -0.074mm for 60% and then performs flotation. After one rough selection and one selection, the copper-nickel concentrate is obtained. A section of rough-choice tailings is further ground to -0.074mm and 70% is sent to the second stage flotation. After one selection, two sweeps, and one selected copper-nickel concentrate. After sweeping the foam, the copper-nickel concentrate was obtained twice. The ore contains 0.5% nickel, the copper-nickel concentrate contains 3.5% nickel, and the recovery rate is about 50%.
The ore-concentrating series of beneficiation processes include three-stage ball milling and two-stage flotation. After the ore is ground to -0.074mm and 70%, the first stage of flotation is carried out, with one rough selection and one selected copper-nickel concentrate. The rough-choice tailings are re-ground to -0.074mm for 80% for the second stage flotation. After a rough selection, two selected copper-nickel concentrates. The second stage of rough selection of tailings is followed by rough selection, sweeping and selection of sulfur concentrate. The ore contains 1.75% nickel, and the copper-nickel concentrate contains 6.5%--7.0% nickel, and the recovery rate is 89%--90%.
Nickel concentrates used in Jinchuan and Jilin Nickel smelters and nickel concentrates used in some nickel plants abroad are listed in the following table.
Chemical composition of nickel sulfide concentrate (%) | |||||||||
Factory | Ni | Cu | Co | Fe | S | MgO | SiO 2 | CaO | Smelting method |
Jilin Nickel Company (middle) | 6.53 | 0.46 | 0.2 | 22.18 | 15.98 | 1.02 | 26.43 | 3.16 | Electric furnace |
Jinchuan Company (middle) | 6.09 | 3.02 | 0.17 | 35.36 | 25.43 | 8.29 | 10.29 | 1.76 | Electric furnace |
Jinchuan Company (middle) | 7.5 | 3.8 | 0.19 | 39.57 | 27.2 | 6.1 | 8.13 | 1.09 | Flash furnace |
Shelter Gordon Mining Company (plus) | 10 | 2 | 0.5 | 38 | 31 |   |   |   | Wet method |
Thompson Nickel Factory (plus) | 7.5 | 0.25 | ---- | 41 | 28 | 2 | 12 |   | Electric furnace |
Tongya Smelter (Plus) | 6 |   | 42 | 28 |   |   |   |   | Blast furnace |
Hajjarta Smelter (Fin) | 6 | 0.5 | 0.24 | 38 | 26 | 7 | 15 |   | Flash furnace |
Old clothes Kalgoli Nickel Smelter (Australia) | 10.57 | 0.93 | 0.19 | 37.05 | 29.58 | 5.53 | 10.13 |   | Flash furnace |
Liuqinsk Smelter (Russia) | 7.63 | 3.57 | 0.34 | 47.86 | 33.02 | 0.44 | 2.04 |   | Flash furnace |
Picker Smelter (Botswana) | 2.9 | 3.4 | 0.2 | 46 | 30 | 1 | 8 |   | Flash furnace |
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