The weighing mixer is characterized by using wind-blown sand and fly ash as the main materials, and cement, quicklime and admixtures and other alkaline materials as auxiliary materials. Through the ground Filling machine, it prepares the filling slurry with a mass concentration (all concentrations are mass ratios, that is, the percentage of solid material mass to slurry mass) of 66% to 75%. The filling slurry is transported by gravity through the filling pipeline and the weighing module to the goaf behind the fully mechanized mining face support underground. After the slurry solidifies, it forms a filling stone body with certain strength in the goaf. As a support system, it can effectively control the damage and movement of overlying rocks, and protect the ecological environment of the mining area by reducing ground subsidence and water-retaining mining. And realize the resource utilization of aeolian sand.

The wind-accumulated sand-like paste fully mechanized mining Filling system mainly consists of three parts: the ground filling machine, the slurry conveying pipeline and the fully mechanized mining filling working face. The filling machine is responsible for the monitoring function of the entire filling system and the preparation of the filling slurry. The preparation of slurry is divided into two steps: preparing the initial slurry and preparing the finished slurry. The initial slurry is made by thoroughly mixing water and fly ash of grade three or above in the corresponding proportion. The finished slurry is made by thoroughly mixing wind-blown sand, cement and auxiliary materials in a certain proportion with the initial slurry. The weighing mixer is temporarily stored in the slurry tank equipped with a stirrer, and under the continuous stirring action, the continuous preparation and output of the slurry are achieved. The slurry is conveyed through the flow control and filtration pipeline system and is transported to the filling working surface by gravity potential energy of the weighing module.

The weighing mixer mainly consists of a discharge station, a granular material storage bin, a vacuum feeding device, a buffer hopper, a level gauge, a feeding device, a metering hopper, a discharge valve and an electrical control system, etc. The mixer conveys the paste to the 20-meter-high material collection hopper through vacuum feeding, and precisely supplies materials to the metering hopper through the feeding device below the collection hopper. Ensure that the weight of the material in the metering hopper reaches the set weight, and finally convey the material to the reactor through the discharge valve. The main function of this mixing system is to lift the larger-sized granular materials to a height of 20 meters on the third floor, providing materials for the weighing mixer. The materials lifted by the vacuum conveyor are unloaded into the buffer hopper. High and low level detection switches are set in the buffer hopper to control the vacuum conveyor to periodically transport the materials into the buffer hopper. The feeding mechanism adopts a three-stage feeding method driven by a cylinder to the sector door to ensure the feeding accuracy. A flexible connection is adopted between the feeding device and the weighing and metering hopper. A Weighing system is composed of three high-quality Weighing modules, a metering hopper and a weighing instrument. To prevent the material from arching and sticking to the wall, a pneumatic exciter is installed on the metering hopper. At the same time, in order to reduce the influence of other devices on the measurement, two flexible connections are respectively adopted at the upper and lower ends of this metering hopper, ensuring the measurement accuracy. The unloading of the metering hopper adopts a rotary unloading valve. The electrical control system is composed of PLC, touch screen, weighing instrument and other parts. Reliable control of the system is implemented through flexible software programming.