利用矿山废弃高塑性红黏土制备轻质陶粒的研究

Research on Preparation of Lightweight Ceramsite by Using Waste High Plastic Red Clay in Mine

生产上多取用农田黏土制备轻质陶粒,以红黏土为主要原料的技术还未见报道。某矿山在开采过程产生大量剥离红黏土,长期堆存无法利用。以该红黏土为主要原料,添加普通黏土、化合物L、石灰石、煤粉进行轻质陶粒制备试验,考察原料配比及焙烧制度对烧成陶粒性能的影响。结果表明,加入适量普通黏土、化合物L可有效降低陶粒烧制过程中的炸裂率,烧成陶粒强度、表观密度随普通黏土、化合物L、煤粉的添加量及焙烧温度的增加而降低,适量添加石灰石可增强烧成陶粒强度;以红黏土、普通黏土、化合物L、石灰石、煤粉质量比为85.5∶7.0∶3.5∶3.0∶1.0混合制得陶粒生球,在105℃下干燥4 h、450℃预热30 min、1 170℃焙烧12 min,可制得轻质陶粒。工业投笼试验所得成品陶粒的关键性能指标均达到GB/T 17431.1—2010中对500级陶粒的质量要求,说明该技术具有实际生产应用价值。研究成果突破了轻质陶粒对原料的严格限制,为矿山剥离高塑性红黏土的高附加值利用提供了新途径。

Up to the present,farmland clay is widely used to prepare lightweight ceramsite,and the technology of preparing lightweight ceramsite by using red clay as the main raw material has not yet been reported. In view of the high pileup of stripped red clay which was produced during mining process in a metallurgical flux mine,the preparation experiments of lightweight ceramsite were carried out by using red clay as the main raw material and ordinary clay,compound L,limestone,pulverized coal as additives,and the effect on lightweight ceramsite＇s performance of raw material ratio and baking system were studied.The results showed that the rate of ceramsite cracking during roasting process and density of ceramsite can be decreased by adding ordinary clay and compound L,and the apparent density and strength of ceramsite can be decreased by increasing calcining temperature and the addition of ordinary clay,compound L and pulverized coal,and the strength of ceramsite can be increased by adding a suitable limestone.The lightweight ceramsite could be prepared if the raw pellets,which prepared with red clay,ordinary clay compound L,limestone and pulverized coal at the mass ratio of 85. 5 ∶ 7. 0 ∶ 3. 5 ∶ 3. 0 ∶ 1. 0,were drying at105 ℃ for 4 h,preheated at 450 ℃ for 30 min and calcined at 1 170 ℃ for 12 min.The key performance indexes of the ceramsite prepared in the industrial test all met the quality requirements of 500 grade ceramsite in GB/T 17431.1-2010,which indicated that the technology has the practical value of production and application. The research results have broken through the strict restrictions on the raw materials of lightweight ceramsite,which provided a new way for the high value-added utilization of high plastic red clay in metallurgical flux mine.