Wolframite and scheelite are the only commercially mined tungsten ores, often accompanied by minerals such as molybdenum, cassiterite, and sulfide ore.
This blog will show 4 successful tungsten processing plants, hoping to give you help.
1. Wolframite processing plant in Canada
A tungsten processing plant in northwestern Canada has the largest tungsten mine in the Western world. Open-pit method is used for wolframite-based tungsten mining. It is the Quartz-Wolframite-Sulfide-type composite mine.
It mainly contains wolframite, bismuthinite, and auxiliary minerals like scheelite, pyrite, pyrrhotite, molybdenite, and chalcopyrite. Surrounding rocks are mainly quartz stone, slate, and phyllite rocks.
The mineral characteristics are deep color (black), coarse particle size (0-150mm), easy to form mud, and raw ore containing 0.47% WO3.
- Capacity : 100 t/h
- Target minerals : wolframite, scheelite, bismuth and sliver.
- Wolframite concentrate grade: Up to 65%.
Crushing - grinding – separation - slime recovery - drying
- Step #1 Crushing: The feeding size is less than 150 mm. The tungsten rock is crushed by a jaw crusher and cone crusher. A vibrating screen can screen the materials and remove the fine powder. The discharging size is between 3-5 mm.
- Step #2 Grinding: As it is easy to form slime, a rod mill is used to grind the ore, avoiding over-grinding. The grinding fineness is -40 mesh.
- Step #3 Gravity separation: The gravity equipment uses a jig and shaking table. The jig is used for roughing and recovering coarse particle wolframite, while the shaking table is for selecting fine-grained concentrate.
- Step #4 Flotation separation: Use a flotation machine to remove sulfides in order to liberate the tungsten. The process flow is mixed flotation of sulfide ore - separation of wolframite by strong magnetic separation - scheelite flotation - wolframite flotation.
- Step #5 Magnetic separation: Use a magnetic separator to remove magnetic minerals, such as pyrite, pyrrhotite, etc.
- Step #6 Recovery of fine tungsten slime: Fine wolframite slime accounts for 10% of the raw ore and the tungsten grade (14%-15%) is higher than the raw ore, so the slime recovery is very important. Ftmmachinery uses gravity and magnetic separation to recover tungsten from slime. The final fine mud recovery rate is increased to 60%-70%.
- Step #7 Drying: After drying with a rotary drum dryer, the water content is 0.3%.
Tips on flotation reagents:
- Use modified water glass to selectively inhibit gangue minerals.
- Use lead salts to activate tungsten minerals.
- Use the new-type chelating collector to do mixed flotation separation of wolframite and scheelite, and the mixed coarse concentrate is heated and selected to obtain scheelite.
- For the selected tailings, use the GY collector to obtain wolframite concentrate.
The WO3 in the concentrate reaches 70.07% and the recovery rate reaches 81.62%.
2. Tungsten-tin ore processing plant in Russia
A tungsten-tin ore processing plant in Russia is an open-pit mine located in the northern Caucasus. The ore is a quartz-cassiterite, wolframite, and clinopyroxene type mine.
The main metal minerals are wolframite and cassiterite, followed by galena, sphalerite, Chalcopyrite arsenopyrite, and Bismuthite. The Gangue are quartz and feldspar. The grade of tungsten oxide (WO3) is 0.26%.
The process flow is rough selection - crushing and grinding - gravity separation - fine mud treatment - fine selection. The production capacity is 60 tons per hour.
- Step #1 Pre-selection: In the mining process, the waste rock mixing rate can reach 60%-80%. Therefore, pre-selection before sorting can discard low-grade waste rock to reduce the amount of ore in the grinding and gravity separation.
- Stage #2 Crushing and grinding: Tungsten - tin ore is relatively brittle, so two-stage crushing and stage grinding are adopted. The crusher uses a jaw crusher and cone crusher. The grinding equipment is rod mill to avoid over-crushing.
- Stage #3 Gravity separation: The coarse concentrate is obtained by gravity separation and discard tailings. That is, the coarse concentrate is obtained by jig and shaking table, and tailings are discarded. The tailings after the medium-grain jigging enter the rod mill for regrinding. The ground product returns to the vibrating screen and then enters the shaking table to produce coarse concentrate.
- Stage #4 fine mud treatment: Fine mud treatment mainly uses gravity equipment, supplemented by the flotation machine to recover more tungsten minerals.
- Stage #5 Fine selection: Regrind the middle ore, secondary concentrate and concentrate respectively. Then use the combined process of flotation-gravity separation to sort out the wolframite concentrate and cassiterite concentrate.
The tungsten concentrate grade reaches 65%.Learn about tin ore processing:
3. Tungsten-molybdenum ore processing plant in South Korea
A 50 TPH tungsten-molybdenum ore processing plant in South Korea is located in Sangdong, which is considered to be the largest tungsten mine in the world. The raw ore is a fine-grained tungsten-molybdenum ore with a grade of 0.13% Mo, 0.35% WO3, and 0.04% molybdenum disulfide (MoS2).
In this ore, the main molybdenum mineral is molybdenite and the main tungsten minerals are scheelite (containing over 95% of tungsten).
A small amount of wolframite can be found as well.
Use the drift and fill mining method for tungsten mining. These zones will be accessed through the 6m x 6m entry and exit channels. Jumbos, shovels, and haulage trucks are used to extract tungsten.
The mined tungsten ore enters the crushing process and flotation process to obtain high-grade tungsten concentrate.
- Step #1 Crushing: The raw ore enters a crushing circuit including a jaw crusher, vibrating screen and cone crusher. The tungsten-molybdenum ore is crushed into 10 mm.
- Step #2 Grinding: Send the crushed tungsten ore to the ball mill and rod mill for two-stage grinding.
- Step #3 Flotation separation: Three-stage floatation plant. The process flow is molybdenum priority flotation, molybdenum coarse concentrate regrinding multiple times, and molybdenum tailings retreatment and Scheelite flotation. The reagents use fatty acids like oleic acid and sodium oleate as the collectors and sodium silicate as the inhibitor of gangue minerals.
- Step #4 Drying: The floating tungsten concentrate is sent to a rotary drum dryer for drying. The water content is controlled by 1%.
The products are molybdenum concentrate powder with 47% molybdenum concentrate grade and tungsten concentrate powder with 65% tungsten concentrate grade.Learn about molybdenum processing:
4. Scheelite processing plant in Uganda
A 50 TPH tungsten processing plant in Uganda mined the tungsten deposit found in quartz veins.
It is coarse-grained scheelite less than 10 cm in thickness with a tungsten trioxide (WO3) grade of 0.73%. Minor wolframite is found as well.
The mining operations use conventional open-pit methods of traditional drill and blast mining with shovel and truck operations.
The project does not require a primary grinding circuit because of its coarse particle size. The tailing dam is also not required, resulting in low capital and operational costs.
- Step #1 Crushing: The jaw crusher (primary crushing), jaw crusher (fine crushing), and roller crusher can form a three-stage crushing circuit to crush the tungsten ore to a particle size of less than 5 mm.
- Step #2 Gravity separation: The crushed tungsten ore is separated by the jig and shaking table. After gravity separation, the WO3 grade is 65%.
- Step #3 Flotation separation: Use a flotation machine to remove sulfides in the coarse tungsten concentrate to obtain qualified WO3 concentrate. The flotation concentrate grade is 30-45% WO3.
- Step #4 Drying: Dry the tungsten concentrate to control the water content by 1%.
The tungsten ore processing technology is crushing and gravity separation, which can achieve a tungsten recovery rate of nearly 78%.
Before processing tungsten, please analyze the mineral composition and properties in order to obtain the optimal beneficiation result.4 tips that can help you:
- When crushing, a jaw crusher is used for coarse crushing. A cone crusher, hammer crusher or roller crusher is selected for fine crushing based on your feed size and output.
- The grinding process mainly uses a rod mill, not a ball mill to prevent over-grinding.
- For tungsten beneficiation, the combined process of gravity, flotation and magnetic separation can get a higher recovery rate. Wolframite mainly uses gravity separation and needs to focus on slime recovery. Scheelite mainly uses the flotation process to separate from minerals such as calcite, fluorite, barite, and quartz.
- If necessary, tungsten concentrate can use chemical beneficiation methods like roasting magnetic method and wet refining method to meet final production needs.