Tungsten, as the "tooth of industry", is a strategic resource in the fields of aerospace, electronics, and military industry. Global tungsten ore resources are unevenly distributed. China, Russia, Canada, and Vietnam are the main reserve countries, of which China accounts for more than 60%. Although China has abundant reserves, it has long faced problems such as low mineral processing efficiency, complex associated minerals, and tailings accumulation. How to achieve efficient utilization and green development of tungsten resources through technological innovation has become the focus of the industry.

1. Types of tungsten ores and associated complexity

Tungsten ores are mainly divided into wolframite (Fe/MnWO₄) and scheelite (CaWO₄). Among them, scheelite (CaWO4) is mostly produced in skarn-type deposits, white or light-colored, with a regular crystal structure, and usually coexists with minerals such as calcite and fluorite. Its mineral processing is difficult and requires the flotation process to separate impurities; wolframite ((Fe,Mn)WO4) is commonly found in high-temperature hydrothermal quartz vein deposits, with a dark brown to black color, and is often associated with gangue minerals such as quartz, mica, and feldspar. Due to the significant difference in density, gravity separation is traditionally used for separation.

In addition, tungsten ore is often associated with metals such as tin, molybdenum, bismuth, copper, and non-metallic minerals such as fluorite and quartz, forming a complex symbiotic (associated) system. For example, tungsten, tin and bismuth coexist closely in a tungsten mine in Jiangxi, and scheelite and molybdenite are intertwined in a mining area in Hunan. This complexity makes it difficult for traditional mineral processing technology to efficiently separate target minerals, and the comprehensive utilization rate of resources is less than 60%.

2. Deep contradictions and technical constraints of traditional mineral processing technology

The bottleneck of traditional tungsten ore processing technology is not only an efficiency problem, but also a complex contradiction between mineralogical characteristics, technical path dependence and environmental protection constraints.

The multi-scale distribution characteristics of tungsten ore (coexistence of coarse, fine and micro-fine particles) put forward differentiated requirements for the process:

Due to the high density of wolframite (7.1~7.5 g/cm³), traditional gravity separation (shaking table, spiral chute) can process +0.2 mm coarse particles, but the recovery rate of -0.074 mm micro-fine particles is less than 40%;

The surface chemical properties of scheelite are similar to those of calcium minerals such as calcite and fluorite. Flotation requires highly selective collectors (such as fatty acids), but the reagent system is complex and easily causes "concentrate contamination".

3. Photoelectric pre-sorting: technical breakthrough and process reconstruction of efficient particle-level sorting

The core value of photoelectric sorting technology lies in the precise control of pre-sorting of particle-level ore (-50mm~+5mm), and the reconstruction of the beneficiation process logic through "early discarding and early fine extraction", so as to achieve rapid purification of ore value density at the source, and lay a low-cost and high-efficiency foundation for subsequent fine-level sorting.

In the traditional mineral processing process, the ore after coarse crushing directly enters the grinding stage, resulting in excessive crushing of a large amount of low-grade waste rock, resulting in energy waste and metal loss. Photoelectric sorting reengineers the process of "crushing-pre-sorting-grading treatment" to intelligently sort the ore after coarse crushing (particle size -50mm), forming three major technical advantages:

Energy density optimization: 30%~50% of waste rock is discarded in advance, which reduces the amount of ore entering the grinding by 40% and reduces the power consumption per ton of ore by 15~20kWh;

Metal flow enrichment: Increase the average grade of ore WO₃ from 0.3%~0.8% to 1.0%~1.5%, and reduce the subsequent flotation reagent dosage by 20%~30%;

Particle size protection: Avoid fine mud caused by over-grinding of waste rock (-0.038mm content is reduced by 12%), and improve the stability of flotation foam.

IV. Tungsten tailings resource utilization: the transformation from waste rock to high-end aggregate

There are more than 1 billion tons of tungsten tailings in my country. Traditional treatment is mainly based on stockpiling, which occupies land and has the risk of heavy metal leakage. Photoelectric sorting technology provides a new path for tailings resource utilization:

Tailings reselection: Use photoelectric equipment to recover tungsten and other valuable minerals from tailings for the second time.

Aggregate value-added: After crushing and shaping, the sorted waste rock can be made into high-standard building aggregates with a particle size of 5~20mm and a compressive strength of more than 60MPa. A tungsten mine in Jiangxi uses this technology to process 500,000 tons of tailings and produce 300,000 tons of aggregates annually.

V. Future Outlook: Intelligence and Collaboration of the Whole Industry Chain

The promotion of photoelectric sorting technology will promote the transformation of the tungsten industry to a low-carbon and circular economy by building a full-process system of "pre-sorting-deep recovery-tailings resource utilization" for tungsten mines.

From "extensive sorting" to "intelligent selection", from "tailings landfill" to "turning stone into gold", the application of optoelectronic technology has not only improved the utilization rate of tungsten resources, but also reshaped the mining value chain.