Reserve a medium-scale deposits of molybdenum, the upper oxide ore to ore-based, the lower portion of the main sulfide ore mining and mining using the mining open binding mode, who is currently based oxide ore beneficiation to stone.
First, the nature of the ore
Mineral composition is relatively simple, the metal is molybdenite minerals, molybdenum China, calcium molybdenum ore, iron ore magnet, followed scheelite, pyrite, copper ore, iron titanium; gangue minerals quartz , feldspar, kaolinite, hornblende, followed calcite, chlorite, mica, white; high molybdenum oxide ores, minerals, and non-argillaceous plus molybdenum of greater non-ferrous minerals molybdenum flotation Influence, the ore is a refractory molybdenum mine.
The results of the multi-analytical multi-analysis (%) were: Mo 0.34, WO 0.14, Cu 0.02, S 0.58, Fe 3.36, SiO 2 66.8, Al 2 O 3 11.91, CaO 2.40, MgO 0.61. The main mineral composition and content (%) in the ore are: molybdenite 0.18, molybdenum 0.13, molybdenum ore 0.32, scheelite 0.17, pyrite 0.42, hematite 3.90, quartz 57.5, feldspar 9.6, calcite 1.8 . The results of analysis of the ore molybdenum phase are shown in Table 1. The ore molybdenum oxidation rate is 68.5%.
The main mineral inlay characteristics are: molybdenum ore is mainly symbiotic with quartz, others account for 1.82% in pyrite and 0.55% in hematite; molybdenum oxide is mainly distributed in gangue fissures, showing pale yellow or earth. The yellow aggregates, most of which retain the shape of the molybdenum crystal, are easily weathered and muddy. Minerals are unevenly embedded in coarse and fine, mainly fine particles; scheelite is closely associated with quartz, and it is rare to have a symbiotic relationship with iron minerals.
Second, the beneficiation test
(1) Grinding fineness test
Molybdenum oxide in ore is easily muddy, and equipment with selective grinding action should be used. Through the comparison test, the roller crushing and the rod mill are beneficial to avoid the loss of molybdenum oxide muddy. Therefore, the selective grinding equipment is used for the grinding fineness test. The flow is shown in Fig. 1, and the result is shown in Fig. 2.
Fig. 2 Relationship between grinding fineness and grade and recovery rate of molybdenum sulfide coarse concentrate
Fig. 3 Relationship between grinding fineness and grade and recovery rate of molybdenum oxide coarse concentrate
The results show that as the grinding fineness becomes finer, the grade and recovery rate of molybdenum sulfide concentrate increase, the grade and recovery rate of molybdenum oxide concentrate decrease, and the grinding grain size is too coarse, and the molybdenite dissociation is insufficient. The recovery rate of molybdenum sulphide is low, so the choice of grinding fineness - 200 mesh is 70%.
(1) Sulfide ore flotation
Molybdenum sulfide flotation using kerosene as collector, frother oil # 2, via a secondary scavenging roughing, direct selection of five rougher concentrate, middlings sequence returns and other conventional agents and processes Molybdenum The results are shown in Table 2.
(3) Molybdenum oxide flotation
The flotation test is carried out with molybdenum sulfide flotation tailings as flotation feedstock of molybdenum oxide. The molybdenum oxide ore is poor in floatability and has little difference from the flotation property of gangue minerals. It is necessary to change the floatability by adding a mineral processing agent; The selection of molybdenum oxide flotation collector and regulator is very important. The conventional oleic acid and 731 oxidized ore collectors are used because of their strong collection performance, poor selectivity and large dosage. The cost is higher [1] ; in addition, the floatability of molybdenum oxide minerals is less than the floatability of calcium-containing gangue minerals, and the grade of concentrate obtained is very low. Therefore, it is necessary to select a relatively good selective oxidation ore. Collecting agent. Through comparison experiments, RT was selected as the molybdenum oxide ore collector, and the dosage and selectivity of the agent were good. The test results are shown in Figure 4. The results show that the amount of collector is relatively small, and as the dosage of the agent increases, the recovery rate increases and the concentrate grade decreases. Therefore, the dosage of the collector is preferably 500 g/t.
Fig. 4 Relationship between the amount of collector and the grade and recovery rate of molybdenum oxide coarse concentrate
(4) Inhibition dosage test
Since the floatability of molybdenum oxide is very similar to the floatability of gangue minerals such as fluorite and calcite in the ore, it is necessary to suppress the gangue mineral by adding selective inhibitors [2] . The experimental results show that conventional water is used. The glass inhibitor also has a strong inhibitory effect on the molybdenum oxide mineral, and the modified water glass can reduce the inhibition of molybdenum oxide and enhance the selectivity of the inhibitor, thereby facilitating the higher cooperation of the collector. The concentrate grade; the test selected modified water glass as the molybdenum oxide ore adjuster, the test results are shown in Figure 5. The results showed that the selectivity of the agent was good.
Figure 5 Relationship between the amount of inhibitor and the grade and recovery of molybdenum oxide coarse concentrate
Figure 5 shows the effect of the amount of inhibitor on the grade and recovery of molybdenum oxide concentrate. Due to the influence of slime, the amount of inhibitor is positively correlated with the recovery rate in the range of 2500g/t. As the amount of inhibitor increases, the recovery rate decreases and the concentrate grade increases. When the inhibitor dosage exceeds 2000g/ After t, the molybdenum recovery rate is drastically reduced, so that the amount of the inhibitor is preferably selected to be 2000 g/t.
(5) Selected trials
The coarsely-selected molybdenum oxide concentrate contains a large amount of calcite, fluorite and a small amount of barite . These gangue minerals have a great influence on the subsequent processing of the molybdenum oxide concentrate and must be selected. The concentrate is concentrated and decontaminated with coarse concentrate. After concentration, the slurry is heated to 85 ° C, kept for 4 h, added with water glass 5-8 kg/t, then diluted to 35%, and then selected twice for one time. The selection process was selected, and the selected mines were returned in order, yielding a test index of 0.79% yield, 27.65% oxidized ore concentrate grade, and 87.83% recovery rate of selected operations.
(6) Comprehensive condition test
The grinding fineness is selected to be -200 mesh, 70%, the molybdenum sulfide flotation is kerosene as the collector, and the 2# oil is the foaming agent. After one rough selection, the crude concentrate is directly selected five times. The conventional ore-selecting molybdenum agent and process flow in the order of returning the mine; the oxidized ore adopts lit as the collector dosage of 500 g/t, the inhibitor modified water glass dosage exceeds 2 000 g/t, the coarse concentrate concentrates and removes the drug, and the heating The selected process flow finally obtained the test indicators as shown in Table 3.
Third, the conclusion
(1) The natural molybdenite deposit is an easy-selected sulfide ore, but the ore molybdenum in this ore area is mainly composed of molybdenum and molybdenum-calcium ore oxidized ore, and its floatability is reduced [3] , and the ore contains a large amount of slime. Difficult to choose ore.
(2) The recovery of molybdenum oxide ore is mainly based on flotation [3,4] , and the flotation reagent must have better selectivity; the molybdenum oxide should be avoided in the selection of the crushing process, and the ore dressing index is closely related to the flotation equipment . .
(3) The selection of molybdenum oxide ore is difficult to achieve a satisfactory concentrate grade, and the pursuit of concentrate grades on the high recovery rate has a great impact.
(4) The molybdenum oxide concentrate obtained by beneficiation has a low grade and a high impurity content. After chemical treatment, the molybdenum oxide product can be obtained, and the obtained molybdenum oxide product has a molybdenum grade of 47.18%, and the operation recovery rate can reach 81.82%.
references:
[1] Wang Dianzuo. The principle and application of flotation agent [M]. Beijing: Metallurgical Industry Press, 1982.222.
[2] Zhu Jianguang. Flotation agent [M]. Beijing: Metallurgical Industry Press, 1993.140-141.
[3] Lin Chunyuan. Molybdenum ore beneficiation and deep processing [M]. Beijing: Metallurgical Industry Press, 1996.
[4] Chen Jianhua, Feng Qiming. Current status of molybdenum ore dressing [J]. Mineral Protection and Utilization, 1994, (6): 26-28.
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