中国矿山工程

The strength of backfill is one of the key factors in the research of cut-and-fill mining technology, which directly affects the safety production and improvement of economic benefits of a mine. The evolution of mechanical properties of backfill under microwave heating is studied herein, which provides a new idea on improving the early strength of backfill. By orthogonal experiment, the influence pattern of each factor on backfill strength is studied and the influence level of each such factor is obtained, based on which the factors are arranged in a descending order as cement-sand ratio, density, power, heating time and microwave intervention time. With the increase of microwave power and microwave heating time, the strength of backfill shows a trend of raise followed by fall, and it decreases with the increase of microwave intervention time. The effect of microwave heating on strength improvement of backfill is more obvious in the backfill with higher cement-sand ratio and pulp density.