Common tungsten ores in nature include scheelite, wolframite and black and white symbiotic tungsten ores. Among them, wolframite is easy to be selected, but with the continuous deepening of tungsten mining around the world, wolframite is becoming less and less, and currently the difficult-to-process scheelite and black and white symbiotic tungsten ores have become the mainstream. This article introduces the beneficiation process and beneficiation equipment of these three common tungsten ores.
1.1. Ore dressing process
Wormite is an easy-to-select tungsten ore. Generally, only gravity separation is needed to obtain good process indicators. The principle of "early collection of jigging and tailings discarding in shaking table" should be followed in the design of ore dressing process. The process flow of wolframite ore dressing is as follows:
(1) Roughing: In the roughing stage, a jig is used for the first roughing of fine particles, and then directly enters the concentrating operation;
(2) Gravity separation: In the gravity separation stage, multi-stage jigging, multi-stage shaking table, and medium ore re-grinding and gravity separation processes are mostly used. After fine crushing, qualified ore is graded by vibrating screen and then multi-stage jigging is carried out to produce jigging gravity separation rough sand. The coarse-grained jigging tailings enter the mill for re-grinding. The fine-grained jigging tailings enter the multi-stage shaking table for selection after classification, and the shaking table gravity separation rough sand is produced. The shaking table tailings are discharged into the tailings pond, and the shaking table medium ore is returned for re-grinding and re-selection. The jigging and shaking table gravity separation rough sand enters the concentrating operation.
(3) Concentration: Use a variety of separation processes of flotation-gravity or flotation-gravity-magnetism, and recover the associated elements in the concentration stage. The sulfide ore is removed by coarse and fine particle table flotation (a beneficiation method combining flotation and shaking table) and flotation. The sulfide ore is combined into sulfide ore flotation separation by table flotation and machine flotation. The table flotation and machine flotation wolframite is further re-selected to produce wolframite concentrate. If the wolframite concentrate contains scheelite and cassiterite, wolframite concentrate, scheelite concentrate and tin concentrate are selected by gravity flotation or gravity flotation-magnetism combined process.
(4) Fine mud treatment: Xinhai usually desulfurizes first, and then recovers tungsten minerals through gravity separation, flotation, magnetic separation, electric separation or a combination of several separation processes according to the properties of the fine mud material, and makes comprehensive utilization of the associated metal minerals.
1.2. Ore dressing equipment
Wolframite beneficiation equipment recommended for you: self-centering vibrating screen, 6s shaking table, jig, BF type flotation machine.
2.1. Coarse-grained scheelite
Mineral processing technology: The key to the mineral processing of coarse-grained scheelite is to obtain a high recovery rate and improve the quality of tungsten concentrate. Usually, a combined mineral processing technology of gravity separation and flotation is adopted. The process is as follows:
(1) During the coarse grinding, Xinhai adds xanthate collectors to float out various sulfides first;
(2) During the gravity separation stage, Xinhai uses a shaking table to separate and obtain a part (all) of qualified tungsten concentrate;
(3) Xinhai uses oleic acid collectors to float scheelite in the gravity separation tailings to obtain a rough concentrate containing 10%-25%, which is sent to water smelting for treatment.
Mineral processing equipment: wet grid ball mill, linear vibrating screen, 6s shaking table, XCF flotation machine.
2.2. Fine-grained scheelite
Mineral processing technology: The key to the separation of fine-grained scheelite lies in the roughing section and the concentrating section. In the roughing section, attention should be paid to improving the grade of the rough concentrate. The goal of the concentrating section is to separate the calcium-containing gangue minerals from the scheelite to obtain qualified tungsten concentrate. Fine-grained scheelite is generally processed by gravity separation, flotation or gravity-flotation combined separation. The process is as follows:
(1) Sodium sulfide, cyanide, chromate, etc. are used to inhibit its associated sulfide minerals; water glass, tannin, sodium polymetaphosphate, chromate, etc. are used to inhibit its gangue minerals. Then the pH value of the pulp is adjusted to 9.5-10 with water glass or sodium carbonate, and 11-12 during concentration;
(2) The "lime-flotation" method is adopted. Use lime to adjust the pulp, add sodium carbonate and water glass, and use oleic acid and cyclohexane acid to collect;
(3) Xinhai adopts a large amount of water glass heating concentration method, that is, a certain amount of water glass is added to the low-grade coarse concentrate, heating, steaming, stirring, dehydrating, slurrying, and then multiple concentrations to obtain a high-grade tungsten concentrate.
Ore dressing equipment: straight cylinder energy-saving overflow ball mill, SF flotation machine, JJF flotation machine, high-efficiency stirring tank.
The commonly used ore dressing technology for symbiotic tungsten ores, especially the polymetallic ores with fine-grained scheelite and scheelite, includes strong magnetic separation technology and flotation technology. The key point of process design is to separate scheelite and wolframite from the symbiotic complex polymetallic ores.
3.1. Process flow
(1) Mixed flotation of sulfide ore-mixed flotation of scheelite-heating concentration of scheelite-strong magnetic separation of scheelite tailings-gravity separation of scheelite;
(2) Mixed flotation of sulfide ore-strong magnetic separation of black and white tungsten-scheelite flotation-black tungsten flotation.
3.2. Ore dressing equipment
Common ore dressing equipment for symbiotic tungsten ores includes: high weir spiral classifier, permanent magnetic drum magnetic separator, SF flotation machine, BF flotation machine, etc.
The above introduces the beneficiation technology and equipment for three types of tungsten ores (scheelite, scheelite, and symbiotic tungsten ores). In actual production, the mineral processing method and mineral processing process should be formulated in combination with the mineral processing test data, and the mineral processing methods of other projects must not be applied.
