新阳煤矿高氧化钙煤矸石火山灰活性激发试验研究
发布时间：2018-11-20 09:05
【摘要】：煤矸石的主要矿物成分为高岭石等粘土类矿物,具有潜在的火山灰活性,若将其活化激发后作为胶凝材料一方面可以解决煤矸石无序堆放引起的占用土地资源、污染环境等问题,另一方面可以作为矿山胶结充填材料中的胶凝材料,降低充填开采成本。目前有关煤矸石火山灰活性研究主要集中在氧化钙含量在3%左右的低氧化钙煤矸石,活化过程中未能实现煤矸石中的硅铝分离,导致煤矸石火山灰活性未能充分激发。本文以新阳煤矿高氧化钙煤矸石为研究对象,通过室内试验、理论推导等方法并结合XRD、XRF、离子浓度检测(ICP-AES)等现代测试技术手段对新阳煤矿高氧化钙煤矸石火山灰活性激发进行了研究。首先,通过对新阳煤矿煤矸石矿物成分、化学成分分析发现,煤矸石主要矿物成分为高岭石等粘土矿物,主要化学成分为SiO_2、Al_2O_3且含有较高含量的CaO属于粘土类高氧化钙含量煤矸石具有潜在火山灰活性。其次,通过研究机械活化高氧化钙煤矸石-水泥浆体中煤矸石、水泥水化程度随煤矸石掺量、水胶比、龄期的变化规律发现:⑴浆体中机械活化煤矸石掺量一定时,随水胶比、龄期的增大,煤矸石和水泥水化程度均增大,且煤矸石掺量为30%时,浆体中煤矸石早期水化速率较好,煤矸石掺量为40%时,浆体中水泥早期水化速率较好;一定龄期时,随煤矸石掺量的增大、水胶比的减小浆体中煤矸石水化程度呈减小的变化规律,随煤矸石掺量的增大、水胶比的增大浆体中水泥水化程度呈增大的变化规律;⑵结合试验结果通过对纯水泥水化公式修正,提出了机械活化高氧化钙煤矸石-水泥浆体中水泥和煤矸石水化程度预测模型。再次,在机械活化煤矸石试验的基础上通过对机械-热激发高氧化钙煤矸石热分解规律、电化学规律以及活化高氧化钙煤矸石-水泥浆体相关性能的研究发现:⑴随活化温度的升高,煤矸石物相变化经历了四个阶段:即煤矸石吸附水和结构水挥发阶段、失重稳定阶段、有机碳质等挥发阶段和煤矸石矿物分解阶段,700℃时,煤矸石分解速率达到最大值;⑵高氧化钙煤矸石溶于蒸馏水时,煤矸石中的CaO先与水反应生成Ca(OH)2,形成一个强碱强极性的溶解环境,加速活化煤矸石中活性离子的溶出速率,接着活性Si~(4+)、Al~(3+)与Ca~(2+)、OH~-反应,生成难溶物质;⑶随活化温度的升高,活化高氧化钙煤矸石-水泥净浆粘度值、单轴抗压强度值先增大后减小,700℃时达到最大值,而净浆凝结时间呈相反的变化规律,700℃达到最小值,得出机械-热活化煤矸石的最佳活化温度为700℃。最后,在机械-热复合活化的试验基础上,通过对机械-热-化学激发高氧化钙煤矸石电化学规律和活化高氧化钙煤矸石-水泥浆体相关性能的研究发现:⑴随活化温度升高,各机械-热-化学复合活化高氧化钙煤矸石抗压强度呈上升的变化趋势,随Na_2CO_3与高氧化钙煤矸石质量比的增大,各龄期高氧化钙煤矸石-水泥净浆抗压强度呈降低趋势;随活化温度升高,碳酸钠比例增加,高氧化钙煤矸石-水泥净浆粘度呈增大的变化规律,而浆体初凝、终凝时间呈降低的变化规律;⑵碳酸钠比例和活化温度共同决定了活化后煤矸石在蒸馏水中的电导率值,而活化后高氧化钙煤矸石粉溶液PH主要是受活化温度的控制。
[Abstract]:The main mineral component of the coal stone is a clay mineral such as kaolinite, and has the potential pozzolanic activity. and on the other hand, can be used as a cementing material in a mine cement filling material to reduce the filling and mining cost. At present, the research on the pozzolanic activity of the coal-fired stone is mainly focused on the low-calcium oxide, which has a calcium oxide content of about 3%, and fails to separate the silicon and aluminum in the coal-fired stone during the activation process, leading to the failure of the pozzolanic activity of the coal-fired stone to be fully excited. In this paper, the active excitation of high-calcium oxide in Xinyang coal mine is studied by means of laboratory test, theoretical derivation and other modern test methods such as XRD, XRF, and ion concentration detection (ICP-AES). First, through the analysis of the mineral composition and chemical composition of the coal-fired stone in Xinyang coal mine, the main mineral component of the coal-stone is kaolinite and other clay minerals. The main chemical components are SiO _ 2 and Al _ 2O _ 3, and the higher content of CaO, which belongs to the high-calcium oxide content of the clay, has the potential pozzolanic activity. Secondly, through the study of the change of the degree of hydration of the coal and the cement in the high-calcium oxide-coal-stone-cement paste, the change of the degree of hydration of the cement with the amount of the coal-fired stone, the ratio of the water-to-cement and the age of the cement, it is found that, with the increase of the water-cement ratio and the age, The hydration degree of the coal-fired stone and the cement is increased, and when the amount of the coal-fired stone is 30%, the early hydration rate of the coal-fired stone in the slurry body is good, the early hydration rate of the cement in the slurry body is better when the amount of the coal-fired stone is 40%, and the amount of the coal-fired stone is increased with the increase of the amount of the coal-fired stone at a certain age, The change law of the degree of hydration of the coal and stone in the slurry body of the ratio of the water-to-cement ratio increases with the increase of the amount of the coal and the cement, and the degree of hydration of the cement in the slurry body increases with the increase of the amount of the coal-cement, and the combined test result is corrected by the formula of the hydration of the pure cement. In this paper, the hydration degree prediction model of cement and coal-stone in high-calcium oxide-stone-cement paste is presented. Thirdly, on the basis of the mechanical activation of the coal-stone test, the thermal decomposition of the high-calcium oxide, the electrochemical law and the activation of the high-calcium oxide-coal-stone-cement slurry were studied. The phase change of the coal-fired stone material is subjected to four stages, namely, the adsorption water of the coal-fired stone and the volatilization phase of the structure water, the loss-of-weight stability stage, the volatilization phase of the organic carbon and the mineral decomposition stage of the coal-fired stone, the decomposition rate of the coal-fired stone reaches the maximum value at the time of 700 DEG C, The CaO first reacts with water to form Ca (OH) 2, to form a strong strong strong-polar dissolution environment, to accelerate the dissolution rate of active ions in the activated coal-fired stone, and then the active Si ~ (4 +), Al ~ (3 +) and Ca ~ (2 +), OH ~-to react, to generate insoluble substances; the temperature increases with the activation temperature. The value of the viscosity of the activated high-calcium-oxide-coal-stone-cement is increased, the value of the single-axis compressive strength is decreased, the maximum value is reached at 700 鈩，
本文编号：2344489
[Abstract]:The main mineral component of the coal stone is a clay mineral such as kaolinite, and has the potential pozzolanic activity. and on the other hand, can be used as a cementing material in a mine cement filling material to reduce the filling and mining cost. At present, the research on the pozzolanic activity of the coal-fired stone is mainly focused on the low-calcium oxide, which has a calcium oxide content of about 3%, and fails to separate the silicon and aluminum in the coal-fired stone during the activation process, leading to the failure of the pozzolanic activity of the coal-fired stone to be fully excited. In this paper, the active excitation of high-calcium oxide in Xinyang coal mine is studied by means of laboratory test, theoretical derivation and other modern test methods such as XRD, XRF, and ion concentration detection (ICP-AES). First, through the analysis of the mineral composition and chemical composition of the coal-fired stone in Xinyang coal mine, the main mineral component of the coal-stone is kaolinite and other clay minerals. The main chemical components are SiO _ 2 and Al _ 2O _ 3, and the higher content of CaO, which belongs to the high-calcium oxide content of the clay, has the potential pozzolanic activity. Secondly, through the study of the change of the degree of hydration of the coal and the cement in the high-calcium oxide-coal-stone-cement paste, the change of the degree of hydration of the cement with the amount of the coal-fired stone, the ratio of the water-to-cement and the age of the cement, it is found that, with the increase of the water-cement ratio and the age, The hydration degree of the coal-fired stone and the cement is increased, and when the amount of the coal-fired stone is 30%, the early hydration rate of the coal-fired stone in the slurry body is good, the early hydration rate of the cement in the slurry body is better when the amount of the coal-fired stone is 40%, and the amount of the coal-fired stone is increased with the increase of the amount of the coal-fired stone at a certain age, The change law of the degree of hydration of the coal and stone in the slurry body of the ratio of the water-to-cement ratio increases with the increase of the amount of the coal and the cement, and the degree of hydration of the cement in the slurry body increases with the increase of the amount of the coal-cement, and the combined test result is corrected by the formula of the hydration of the pure cement. In this paper, the hydration degree prediction model of cement and coal-stone in high-calcium oxide-stone-cement paste is presented. Thirdly, on the basis of the mechanical activation of the coal-stone test, the thermal decomposition of the high-calcium oxide, the electrochemical law and the activation of the high-calcium oxide-coal-stone-cement slurry were studied. The phase change of the coal-fired stone material is subjected to four stages, namely, the adsorption water of the coal-fired stone and the volatilization phase of the structure water, the loss-of-weight stability stage, the volatilization phase of the organic carbon and the mineral decomposition stage of the coal-fired stone, the decomposition rate of the coal-fired stone reaches the maximum value at the time of 700 DEG C, The CaO first reacts with water to form Ca (OH) 2, to form a strong strong strong-polar dissolution environment, to accelerate the dissolution rate of active ions in the activated coal-fired stone, and then the active Si ~ (4 +), Al ~ (3 +) and Ca ~ (2 +), OH ~-to react, to generate insoluble substances; the temperature increases with the activation temperature. The value of the viscosity of the activated high-calcium-oxide-coal-stone-cement is increased, the value of the single-axis compressive strength is decreased, the maximum value is reached at 700 鈩，
本文编号：2344489
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