Project Name: 500 TPD Tungsten Sludge Gravity Separation Project

Location: China

Mineral: Tungsten Ore

Processing Capacity: 2600 tons/day

Main Equipment: SL Centrifugal Separator

Processing Technology: Gravity Separation

I. Mine Overview and Original Technology Issues

The Tieshanlong tungsten mine is a quartz vein-type wolframite deposit, with a wolframite to scheelite ratio of 34:1. The mine processes 2,600 tons of ore per day, producing 2,620 tons of tungsten concentrate annually, and approximately 500 tons of primary and secondary tungsten slime per day. The tungsten slime exhibits significant characteristics, with over 98% of particles smaller than 0.074 mm, including 66% of particles between -0.074 mm and 0.037 mm. The WO₃ grade in the slime ranges from 0.1% to 0.3%, while the secondary slime contains up to 0.29% WO₃. The gangue is primarily composed of SiO₂ (68.06%) and Al₂O₃.

The mine originally used the Φ800mm×600mm centrifugal separator from another manufacturer to process tungsten fine mud. This equipment has many shortcomings. Not only is the processing capacity small, but core components such as solenoid valves, alloy drums, and anchor bolts are also prone to damage. Frequent equipment failures directly restrict the beneficiation efficiency, resulting in a tungsten fine mud recovery rate of only 39.52%, which has become a key bottleneck for the efficient utilization of mineral resources in the mine.

II. Core Features of the SLon-1600 Centrifugal Separator

The SLon-1600 Centrifugal Separator is a new type of gravity separation equipment designed for the separation of fine-grained minerals ranging from -0.074mm to +0.010mm. It is suitable for the fine-grained separation needs of tungsten slime and features high processing capacity, low minimum recoverable particle size, and low energy consumption. The core structural parameters of the equipment are a 1600mm diameter and 900mm length drum at the feed end. It operates in an intermittent process, sequentially completing three key steps: feed stratification, discharge of light mineral tailings, and high-pressure water washing of the sediment concentrate. Centrifugal force is used to achieve efficient separation of minerals of different densities.

Figure 1 On-site Application Image

Based on the characteristics of tungsten fine mud in the Tieshanlong tungsten mine, the core operating parameters of the equipment are determined thro

ugh industrial tests: the coarse separation operation speed is 220 r/min, and the feed concentration is controlled at 25% to 30%; the fine separation operation speed is 180 r/min, and the feed concentration is 30%, providing precise parameter support for the efficient application of the equipment in the mine.

III. On-site Mineral Processing Technology

The complete beneficiation process for tungsten slime at the mine site is as follows: After crushing and grinding, the raw ore is separated into coarse minerals and tungsten slime by a classification device. The tungsten slime first enters a high-efficiency thickener for concentration and dewatering to reduce the water content of the slurry to meet the requirements of subsequent separation. The concentrated slurry then enters a desulfurization flotation process to remove sulfide impurities such as pyrite. The desulfurized slurry then enters a centrifugal separation stage (the core separation step). The separated rough concentrate is then further purified by shaking tables to finally produce qualified tungsten concentrate. The tailings from the centrifugal separation are further processed by flotation to recover useful minerals, maximizing resource utilization. The process flow is shown in the diagram below:

Figure 2 Fine mud separation process

IV. Equipment Application and Transformation and Mineral Processing Effects

To address the bottlenecks in the original process, Tieshanlong Tungsten Mine completed the upgrade and renovation of its mineral processing equipment in July 2013. Eighteen SLon-1600 centrifugal separators were used to completely replace the old centrifugal separators. After the renovation, both mineral processing indicators and production efficiency were improved, and the overall equipment operating rate reached 99%, with stable and reliable operation.

1. Tailings grade significantly reduced. Before the upgrade, the WO₃ grade of tailings from the centrifugal separator + shaking table process was 0.105% from January to July 2013. From 2014 to 2016, the tailings grade dropped to 0.099%, 0.065%, and 0.087% respectively, resulting in a significant reduction in resource loss.

2. It significantly improved tungsten sludge recovery rate. The tungsten sludge recovery rate increased significantly from 39.52% before the upgrade to 45.71% in 2014, and remained stable at 41.19% and 41.75% in 2015 and January-July 2016, respectively.