Technological Study And Reliability Analysis Of Yellow Phosphorus Slag And Phosphgypsum Backfill In Kaiyang Mine

Key points about yellow phosphorus slag and phosphgypsum backfill in Kailin Mine Group Co.,Ltd (KLM), such as optimum dosage of backfill materials, hydration mechanism of backfill mixture, backfill process, were studied and realibility of this technology was evaluated in detail in this paper, using comprehensive researching means such as field investigation, laboratorial experiment, scheme design and numerical simulation. The main contents and conclusions are summarized as follows:1.Information retrieval results indicate that there is no any report about yellow phosphorus slag and phosphgypsum backfill technology. In other words, this researching work is the fist trial in mining and backfilling field.2.Physical and mechnical factors of backfill materials as well as their chemical composition were initially measured and analyzed, and then optimun dosages of yellow phosphorus slag and phosphgypsum backfill were given as follows by large amounts of laborotarial tests:(i) mass proportion of yellow phosphorus slag to phosphgypsum is 1 to 4, adding mass of lime slag is 5% of yellow phosphorus slag, and mass fraction of backfill slurry is 57% for delayed backfill;and (ii)mass proportion of Portlamd to yellow phosphorus slag to phosphgypsum is 1:4:15,adding mass of lime slag is 5% of yellow phosphorus slag, and mass fraction of backfill slurry is 60% for surface part of backfill body.3.Slump, dispersion and consistency of backfill slurry indicated that backfill slurry with dosage suggested above had good performance of transportation and could met the requirement of pipeline transportation by gravity.4.Mechninsm of yellow phosphorus slag and phosphgypsum backfill was clarified, combined with Analytical results of chemical and mineral composition as well as influencing factors on hydration degree and scanning observation of microstructure of yellow phosphorus slag and phosphgypsum backfill body.5.Drainage of yellow phosphorus slag and phosphgypsum backfill slurry met the national standards for waste water quality. Qualitative analysis, hydraulic calculation and numerical simulation of yellow phosphorus slag and phosphgypsum backfill suggested that backfill slurry preparation system was reliable and flow of backfill slurry within vertical and horizontal pipeline was smooth and stable.6.It was estimated that direct backfill material cost of yellow phosphorus slag and phosphgypsum backfill was 29.5 Chines yuan per cubic meter,34.7 Chines yuan per cubic meter lower than that of cementd phosphgypsum backfill used present in KLM.Yellow phosphorus slag and phosphgypsum backfill is a creative technology with obvious economical,environmental and social benefit. It can not only solve shortage problem faced with KLM and reduce backfill cost, but also supply an important comprehensive usage way of yellow phosphorus slag and phosphgypsum.It can also raise recovery rate of mineral resources and supply a support to surface structures.