Discuss about Stowing Material for Coal Mine

Mining with stowing is an environmentally friendly way for coal mine, and stowing material is the key to realize environmental protection and harmonious development. This paper focused on the stowing materials, and evaluation for the stowing material would be made. Stowing materials could be sorted as chemical reaction material, solid refuses from coal mine and natural material for stowing. In the light of the cost and sustainable application of the stowing material, we suggest solid refuses from coal mine are the first choice as stowing materials for now.Urban pollutants could be a good kind of stowing materials, but further study should be made for this material. Also the stowing materials should be as cheap and environmentally friendly as they could.

Experimental Study on the Characteristics of Aeolian Sand Paste-Like Stowing Material in Coal Mine

In order to reduce the cost of stowing materials in Yuyang coal mine, and localize the stowing material, a series of experiments were conducted, which were based on the sampling and testing of aeolian sand to analyze the reaction mechanism of paste-like stowing slurry. The influence of different aeolian sand and auxiliary material content on stowing material was also studied in the experiment. Experimental results indicate that the main components of aeolian sand are SiO2 and Al2O3. The stowing material density increases by 23.4% with more aeolian sand additive amount, and the material cost falls to 93 yuan/m3, reduced by 25.6%. With the increase of auxiliary gelatinization material dosage, the 28-day strength of material increases by 59.4%, the hardening rate of stowing material reaches up to 109.5%, increased by 23%, and the stowing material shows micro expansion.

Mechanism of Coal Mining and Stowing with Upper Entry for Preventing Coal Bump

The material failure induced coal bump and structure failure induced coal bump were paid attention to in this paper. Mechanism of coal mining and stowing with upper entry for preventing coal bump was analyzed. The mechanism of mining with upper entry for preventing material failure induced coal bump is that the stowing material can recover the integrity of the cracked roof, and for preventing structure failure induced coal bump is that water infusion to the roof could release the energy in the roof, and the backfilling could support the roof, both of them could change the stress condition of the roof. It hopes that coal mining and stowing with upper entry for preventing coal bump is a rational way to realize safety mining, but there still are some questions should be the further studied.

Experimental Research and Application of Mining with Paste Material Stowing

Mining with filling technology is not only an important part of green mining but also the ideal methods to solve the environmental issues in coal mining. The coal gangue and fly ash and furnace slag were selected as the stowing material and the SL paste as cementing material. These two kinds of material were processed into a toothpaste-like slurry without dehydration on ground and transport to underground with the help of gravity or stowing pump in order to stowing the goaf and control the movement of superincumbent strata .Industrial test at Xinsan colliery showed that such kind of paste filling material has high early strength, when filling body was used for false roof of work-face, the post-strength requirement of paste filling material can ensuring false roof stability.