| Since the backfill mining method application, the tails backfill hold dominant position. Because the tailing has no optional to do, so people usually don’t consider the gradation of the tailings. In the recent years, along with the appearances of stone filling, coarse rods matte fill, waste rock+tailings filling mode and so on, in the mine backfill design we have to consider the gradation question. But until now, coarse aggregate pipeline filling process in the mines are still rarely, And on the pipeline under the conditions of the gradation of coarse aggregate, concentration and strength design of other aspects of research are basically blank. This thesis systematically studied the coarse aggregate in high concentration pipeline self-flow filling technology, including the coarse aggregate gradation, intensity, concentration and flow condition. And a test of the underhand drift type coarse aggregate high concentration pipeline self-flow filling technology was successfully took in the JinChuan mine.Based on the research and the application analysis of the concrete aggregate gradation, we point out that we can apply the Talbol method to carry on the aggregate gradation analysis and optimization of mine coarse filling. And an analysis had carried on to the broken waste rock aggregate and the Gobi coarse sand’s gradation of the JinChuan mining area. Obtained that the JinChuan Mining-8mm～-12mm grain size of the crushing of waste rock aggregate gradation index is n≈0.42～0.38, and the-8mm size crushing Gobi aggregate gradation index is n≈0.42. The coarse aggregate above can be directly used for preparing high concentration pipe filling slurry, while the-16mm and-20mm waste rock aggregate and crushing Gobi aggregate must match with the corresponding proportion of total tailings. According to the intensity of the orthogonal test that:in the same condition of cement dosage and the weight concentration, the bigger the aggregate accumulation density is, the higher strength of test block is. And under the condition of same cement dosage, with the decrease of water cement ratio, the strength of test block increase observably. Under the condition of the same concentration, the greater the cement sand ratio is, the higher the strength is. Compared with the single aggregate and the mixing aggregate, with the increase of water cement ratio, strength did not sharply reduce as the decrease of the cement content. Therefore, the strength of aggregate gradation is very obvious, we need to optimize the sand-lime ratio. And proposed that the condition of the coarse aggregate pipeline filling slurry with high concentration through a lot of experiments:if the coarse aggregate filling material can keep stratification in statically for a certain period of time, then the concentration is high. The range of the coarse aggregate filling material is small, and varies with the amount of the fines content. The more fine aggregate is, the greater the range of the high concentration. And at the same time puts forward the high flow condition of the coarse aggregate of high concentration slurry:the average slump of the slurry should>220mm. the expansion of degree should>450mm. Slurry of fine-grained (powder) materials should to be able to carry the coarse aggregate. Fine-grained (powder) materials must be fully filling in the gap of the coarse aggregate. The slurry in the mined approach should be close to the status of the self-leveling.Based on a large number of indoor experiments, the high concentration pipeline self-flow filling technology was successfully tested in the next to the level hierarchical approach type mine. With the features of high concentration, high flow, self-compacting, low cost. And it has the both advantage of the high-concentration gravity filling and the paste pumping filling. And it is a low cost mining thick bone filling new technology. As the experiments show:according to the adoption of coarse aggregate, the cost of filling was greatly reduced, so the vast majority of mine can afford. |
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