Study On New Paste Filling Material Based On Industrial By-product Fluorogypsum

Paste filling has the outstanding advantages of high solidification strength,simple filling process,low filling cost and large consumption of solid waste such as coal gangue and fluorogypsum,especially for the surrounding mines with many solid waste resources have high application prospects.At present,the cementitious material used for paste filling material is mainly cement,and with the significant increase of cement price,the cost of filling mining is also increasing day by day,while fluorogypsum is an industrial by-product,the main component is anhydrous calcium sulfate,which is a cheap material with good cementing performance that is being developed and utilized nowadays,and the development of new paste filling material by using fluorogypsum can not only effectively reduce the cost of filling material,but also The development of new paste filling materials using fluorogypsum can not only effectively reduce the cost of filling materials,but also realize the harmless utilization of fluorogypsum,which has high economic value and social and environmental value.（1）It is feasible to use fluorogypsum as cementitious material to formulate new paste filling material.Fluorogypsum replaces cement in the preparation of filling materials,and the solidification strength and flow characteristics of the filling body are basically equivalent to those of cement-based filling materials,but the cost per unit of material can be saved by 62.46%,which can bring great economic benefits to the mine.（2）The basic ratio of new fluorogypsum-based paste filling material is determined as follows:1000g of coal gangue,300g of fly ash,300g of fluorogypsum,50g of lime,and the mass concentration is 78%,and its 1d strength is 0.88MPa,7d strength is0.98MPa,28d strength can reach 4.28MPa,slump is 246mm,extension is 440mm,water secretion rate is 2.92%,the material has good mechanical properties and flowability.（3）The three main materials of the developed new fluorogypsum-based paste filling material are all solid waste resources,which have higher social value.（4）The hydration products of the fluorogypsum-based paste filling material are mainly calcium alumina（AFt）,calcium sulfate dihydrate（CaSO₄·2H₂O）and SiO₂,and the hydration products are closely lapped and compact,which makes the material have high compressive strength.There are 79 figures,13 tables and 61 references in this paper.