The wolframite ore has a high depletion rate, low grade, coarse grain size, high density, low hardness, easy mud formation and deep color, which is mainly extracted by the gravity separation process. China’s wolframite ore beneficiation production has a history of more than 70 years and has accumulated rich experience, which can be summarized as the following parts.
1. Pre-enrichment, early throwing the waste rock, then washing, desliming, grading, crushing.
The dilution ratio of wolframite mining is generally around 80%. The amount of surrounding rock in the ore is large, and are easy to distinguish with wolframite containing rock. Pre-select the waste rock increases the beneficiation processing capacity and efficiency, and reduces the rock crusher wear.
2. Gravity separation, grading and sorting. Jig concentrator – shaker table to recover the coarse particle wolframite.
3. Fine wolframite slime concentration
Fine wolframite slime includes primary and secondary slime, which accounts for about 10% of the original ore. The tungsten grade is higher than the original ore, grade is 14% to 15%. Extract tungsten from slime is an important method for improving the tungsten recovery rate.
Wolframite slime concentration machines have shaker tables, centrifugal concentrators, belt chute, flotation, magnetic separation. The fine mud recovery rate has increased from 10% ~ 50% to 60%~70%.
Case study: wolframite plant
Take the Pangushan tungsten wolframite plant as an example, further explore the tungsten ore processing flow and technique.
Mineral composition: Quartz-wolframine-sulphide type composite deposit, mainly contains wolframite, bismuthinite, auxiliary minerals like scheelite, pyrite, pyrrhotite, molybdenite and chalcopyrite.
Surrounding rocks mainly in quartz stone, slate and phyllite rocks.
wolframite, scheelite, bismuth and sliver.
【Extraction & beneficiation】
Crushing – washing – hand picking – grinding – jig concentrator – shaker table – flotation – magnetic separation.
complete processing flow divided into 4 parts, primary separation, gravity separation, slime recovery, and concentration.
| ||#1 Crushing|| ||T/H(set)||Feeding size(mm)||Discharge size(mm)||Ore loose density|
|Coarse crushing||400*600 jaw crusher||1||60||<150||<92||1.7|
|Medium crushing||250*500 jaw crusher||2||24~26||<25||<20||1.7|
|Fine crushing||750*500 roller crusher||2|| ||FALSE||3~5||1.7|
| ||#2 Grinding & grading|| ||T/H(set)||Feeding size(mm)||Grinding fineness|
|Stage 1||900*2400 rod mill||4|| ||-10||-2.5mm|
|Stage 2||900*2400 rod mill||1|| ||-2.5||-40mesh|
| ||#3 Flotation, gravity, magnetic separation|| ||T/H(set)||Concentration||Feeding size(mm)|
|Flotation||Flotation machine||12|| ||30%~35%||-80 mesh|
|Magnetic separation||Three disc magnetic separator||3|| || ||-60/-1.8mm|
|Gravity separation||Spring shaker table||8|| || || |
| ||600*600 jig concentrator||8|| || || |
| ||800*700 centrifugal concentrator||24|| || || |
| ||Belt chute||8|| || || |
| ||#4 Dewatering|| ||T/m2||Feed material moisture%||Discharge material moisture%|
|Dryer||Tungsten drying oven 600*5000||2||60.1||11||0.3|
| ||Bismuth drying oven 600*4400||1||71.15||22.6||0.21|