On August 31, 2019, the China Coal Industry Association organized experts to conduct technical evaluations on the research and application of the S-3GHMC series super pressure free feeding heavy medium cyclone jointly completed by Guohua Technology and Huaibei Mining Co., Ltd. Linhuan Coal Preparation Plant, as well as the application research of Guohua Technology coal selection process package in millions of ton coking coal preparation plant jointly completed by Guohua Technology and Huainan Mining (Group) Co., Ltd. Coal Preparation Branch.

The appraisal committee, consisting of ten members, including Academician Sun Chuanyao of the Chinese Academy of Engineering as the chairman, Professor Zhang Mingxu, the doctoral supervisor of Anhui University of Technology, as the vice chairman, and Researcher Liu Feng, the vice president of the China Coal Society, listened to the reports of the project completion units. After questioning and discussion, they unanimously passed the technical appraisal of the two achievements.

（1） The S-3GHMC series super pressure free feeding heavy medium cyclone is based on the national key new product 3GHMC series pressure free feeding three product heavy medium cyclone. It optimizes the structural form and parameters, reduces the resistance inside the cyclone, and allows materials of different densities to enter the high and low density areas of the cyclone more quickly; Increase the radial velocity gradient of the heavy suspension in the cyclone, reduce the structured viscosity, and increase the solid-liquid ratio; Significantly adjust the diameter ratio of the two-stage cyclone and the cone ratio of the two-stage cyclone to break through the limitation of the three product cyclone on the amount of waste discharged. As a result, the processing capacity, gangue discharge capacity, and upper limit of feed particle size of the three product heavy medium cyclone have been doubled. Taking the S-3GHMC870/410 model with a diameter of 1300mm, processing capacity of 870t/h, and waste discharge capacity of 410t/h used in the production of Linhuan Coal Preparation Plant as an example, the measured average processing capacity is 810 t/h. The K value that characterizes the processing capacity of the heavy medium cyclone reaches 455, which is more than twice the K value of well-known domestic and foreign brands of heavy medium cyclones; Possible deviations include Epm1=0.033kg/L and Epm2=0.027kg/L; the power consumption per ton of coal in the cyclone is 0.96kW · h.

The committee members believe that the processing capacity of the new structure's super three product heavy medium cyclone has increased by more than 100% compared to similar cyclones, with a single system processing capacity of up to 5.0Mt/a. It is also suitable for high gangue raw coal, simplifies the coal selection process, improves labor productivity, and reduces electricity consumption by 30% compared to traditional heavy medium cyclones. It has achieved good economic and social benefits and reached the international leading level.

（2） The 12.0Mt/a Panji Coal Preparation Plant of Huainan Mining (Group) Co., Ltd., which was put into operation in March 2018, adopts a three product heavy medium cyclone with no pre discharge, no classification, and no desliming of raw coal developed by Guohua Technology; A coal slurry heavy medium cyclone without the need for separate preparation of ultrafine media; Fine coal slurry two-stage (twice) jet flotation machine separation and two-stage dewatering of clean coal slurry; Two stage concentration and two stage recovery of tailings slurry water; And intelligent technology process packages such as production centralized control, heavy medium, and automatic measurement and control of flotation process parameters. After testing, it was found that the three product heavy medium cyclone may have a deviation of Epm1=0.027 kg/L, Epm2=0.039 kg/L, and a lower separation limit of ≤ 0.25mm; The lower limit of coal slurry heavy medium cyclone separation is ≤ 0.10mm; The comprehensive improvement index of fine coal slurry desliming and coarse fine flotation is 55.58%; Water consumption per ton of coal is 0.07m3, electricity consumption per ton of coal is 7.26kW · h, and medium consumption per ton of coal is 0.81kg.

Given that Guohua Technology has been dedicated to the unremitting research and development of coal preparation technology for many years, as well as its outstanding contributions in coal preparation processes and equipment, the attending members unanimously believe that the "Guohua Technology Coal Preparation Process Package" has strong applicability to coal quality, simple process, low investment and operating costs, and has achieved good economic and social benefits in the research and application of Panjite Large Coking Coal Preparation Plant, achieving international leading levels.

The appraisal committee suggests further strengthening the promotion and application of the two achievements.