Effect analysis of non-desliming washing process for high-slime raw coal

WANG Hao; WANG Liehong; HE Huitong; TONG Jie; ZHU Guomeng; DONG Lilan; HU Jianfeng

doi:10.16447/j.cnki.cpt.2025.05.008

Abstract：In coal preparation practice,when the slime content of raw coal is high,pre-desliming is typically in-corporated into the process design to prevent excessive slime from negatively impacting separation efficiency.To simplify the processing circuit and explore the feasibility of non-desliming separation for high-slime raw coal,this paper presents a quantitative calculation of slime content in the separation medium.Taking the Xieji-ahegou Coal Preparation Plant in Guizhou as a case study,it introduces the practical application of a combined circuit:primary separation with non-desliming pressureless-fed three-product heavy medium cyclones(HMC)+coarse slime separation with coal slime HMC+fine slime flotation.Operational results demonstrate that:the primary three-product HMC obtained satisfactory separation results,such as,the average gangue loss in clean coal is 0.29%,the average coal loss in middling coal is 0.84%,the average coal loss in gangue is 0.08%,and maintained an average throughput of 420～450 t/h,reaching a maximum of 520 t/h.Production statistics from January to September 2024 show that despite a primary slime content of approximately 25%(and a total slime content of roughly 40%including secondary slime),the plant maintained a magnetite consumption of less than 1.0 kg/t and power consumption of 6.0 kW·h/t.The successful implementation of the non-desliming process for high-slime raw coal at Xiejiahegou Coal Preparation Plant indicates that,through rational process design,proper equipment selection,optimization of the medium recovery circuit,and the implementation of effective management measures,the non-desliming process achieved high efficiency and low consumption.