Recently, TDS "intelligent" dry separation technology seems to have attracted attention from the coal preparation industry in China.

At the "Beijing Guohua Technology Group Coal Preparation New Technology Seminar" held in Tangshan from February 28th to March 1st, Researcher Zhao Shuyan, Chairman and Chief Engineer of Guohua Technology Group and a renowned coal preparation expert, repeatedly emphasized that the "Large scale, Efficient, and Simplified Heavy Medium Cyclone Coal Preparation Technology" proposed by China during the Ninth Five Year Plan period has always been the development direction of world coal preparation technology, whether in the special report "Today's Guohua Technology Coal Preparation Technology" or in interactive exchanges with guests. The United States is the pioneer of heavy medium lump coal separators, and even Robert W. Hollis, the chairman of its coal preparation association, holds the same view. He stated at this meeting that although shallow groove separators are still popular in some coal preparation plants, the application of non graded mixed large-diameter heavy medium cyclones is the trend.

The latest S-GHMC series super heavy medium cyclone developed by Guohua Technology not only has a single machine processing capacity of 1300t/h, but also has a super strong gangue discharge capacity of 910t/h, and the upper limit of the feed coal particle size exceeds 200mm. It not only eliminates the raw coal desliming system, but also makes all pre discharge systems redundant. The super heavy medium cyclone has been successfully put into operation in coal preparation plants such as Zhongheng in Guizhou and Nanguan in Shanxi. According to testing, the Zhongheng Coal Preparation Plant, which selects alternative raw materials such as coal, may have a deviation of 0.022kg/L in the first stage and 0.034kg/L in the second stage; Gangue belt -1.8kg/L density grade coal 0.79%, clean coal belt 1.8kg/L density grade gangue 0.00%.

The TDS "intelligent" dry selection technology first involves spreading the raw coal flat, using sensors and big data analysis to digitally identify coal and gangue, and then separating the coal and gangue through high-pressure air. This technology consists of main components such as feeding, fabric distribution, X-ray identification, execution, as well as auxiliary equipment such as air supply, dust removal, power distribution, and control. Although the system is complex and costly, the sorting accuracy is very low. The three test results of Jinmei Zhaozhuang Coal Preparation Plant, listed in the relevant report by the R&D team on October 27, 2016, showed that the visible coal in the 300-100mm grade gangue belt was as high as 2.26%, 2.18%, and 2.19%, respectively! It should be noted that the gangue carrying coal described by the developer is manually "picking out coal blocks", that is, "visible" lump coal.

In the coal selection industry of our country, "gangue with coal" refers to the density level content of -1.8kg/L in gangue, rather than the "visible" coal content in gangue. The three product heavy medium cyclone developed by Guohua Technology has a density grade content of -1.8kg/L in the discharged gangue. Even when intentionally reduced to 5%, the "visible" coal, especially lump coal content, remains zero.

In today's highly efficient and simplified mixed heavy media elimination of graded heavy media - just like in the past when mixed jigging eliminated graded jigging - even high-precision shallow groove heavy media waste discharge is gradually being phased out of the market. Is it appropriate to promote pre discharge systems such as TDS, which have high investment, low sorting accuracy, and make the system complex? Worth thinking in the coal selection industry.

Researcher Zhao Shuyan finally reminds colleagues in the coal selection industry to carefully examine new technologies, distinguish between fake and genuine, and conduct in-depth and meticulous technical and economic analysis to avoid wasting investment.