我国石灰岩矿产资源丰富，但由于利用粗放，导致资源的巨大浪费和环境破坏。无疑，对石灰岩进行资源精细化深加工是实现这一资源效益最大化重要途径，具有非常重大的意义。本文在对渭北奥陶纪石灰岩有机杂质处理的基础上，制备出了质量良好的重质碳酸钙；进而，对重质碳酸钙进行改性，有效提高了重质碳酸钙活化度、沉降体积和吸油值等方面的性能。研究成果对于拓展研究区石灰岩的利用途径、提高效益、减少环境污染具有重要参考价值。 首先，对渭北奥陶纪石灰岩进行预处理，去除其中杂质。利用石灰岩与有机质的分解温度差异，通过低温煅烧去除石灰岩中的有机质。低温煅烧去除有机质的最佳工艺条件是：石灰岩粒度-0.074mm，煅烧温度650℃，升温速率5℃/min，煅烧时间16h。最佳工艺条件下，石灰岩白度从38%提高到92%。 其次，采用球磨机和分级机配合工艺流程，利用处理后的石灰岩制备重质碳酸钙。研究了磨矿介质配比、磨矿时间、入料质量、介质填充率和球磨机转速等5个参数对重质碳酸钙粒度和性能的影响；得到的重质碳酸钙最佳制备条件是：球介质配比为6:3:1、磨矿时间为7min、入料质量为60g、介质填充率为40%和球磨机转速选择200r/min，此时粒度小于10μm的重质碳酸钙达到55.9%。 最后，对重质碳酸钙进行了改性。以十二烷基苯磺酸钠为改性剂，探讨了料浆浓度、改性剂温度、改性时间、改性剂用量和搅拌速度等5个单因素对改性效果的影响，得出各因素的最佳值为：料浆浓度3%、改性剂温度70℃、改性时间40min、改性剂用量8‰wt(CaCO3)、搅拌速度1050r/min；该条件下改性重质碳酸钙活度达90%。通过正交试验，分析了料浆浓度、改性剂温度、改性时间和改性剂用量等4个主要因素的影响，获得了这些参数的最佳改性条件分别是：3%、70℃、50min、8‰wt(CaCO3)，此时活化度可达91.2%，沉降体积为1.2mL/g，吸油值为0.25。 通过对改性后的重质碳酸钙红外光谱分析发现，十二烷基苯磺酸钠有效包覆在了重质碳酸钙表面；显然，重质碳酸钙性能的提升是改性的结果。

Limestone deposits in China are very rich. However, the extensive use of resources results in a huge waste of resources and environmental damage. Undoubtedly, it is an important way to realize the maximization of resource efficiency by the fine processing of resources, which has a great significance. In this paper, Based on processing of Weibei Ordovician limestone, we have prepared a good quality of heavy calcium carbonate. Then, we modified the heavy calcium carbonate, which can effectively improve the performance of the degree of activation, sedimentation volume and oil absorption value of ground calcium carbonate, etc. The research results have important reference value for expanding the utilization of limestone in the study area, improving the efficiency and reducing the environmental pollution. Firstly, we pre-process the Weibei Ordovician limestone to remove the organic impurity. Due to the different decomposition temperatures between limestone and organic matter, we can remove the organic matter by the methods of low temperature calcination limestone. Getting the optimum conditions: limestone sample size was -0.074mm, calcined temperature was 650℃, heating rate was 5℃/min, calcination time was 16h, cooling by the way of interior cool. Under this above optimum conditions, the whiteness of limestone can be increased from 38% to 92%. Secondly, we use a ball mill and classifier process to produce heavy calcium carbonate with the purified limestone. Studying on the effect for the particle size and properties of heavy calcium carbonate of the 5 parameters of grinding media ratio, grinding time, feed quality, medium filling ratio and ball mill rotating speed. The best preparation condition of the heavy calcium carbonate is that: ball media ratio was 6:3:1, grinding time was 7min, feed quality was 60g, media filling rate was 40% and mill speed selected 200r/min. When the heavy calcium carbonate of which particle size is less than 10μm can be achieved 55.9%. Finally, we have modified the heavy calcium carbonate. Used Sodium dodecyl benzene sulfonate as modifier to modify. Through investigating of 5 factors on the modification effect, we got the optimum value of each factor: the concentration slurry was 3%, the modifier temperature was 70℃, the modification time was 40min, the amount of modifier was 8‰wt(CaCO3), the stirring speed was 1050r/min. Under this above conditions, activity of the modified heavy calcium carbonate can be up to 90%. We used orthogonal experiment to analysis the combined effect of slurry concentration, modifier temperature, modified time, and the amount of modifying agent and to find the best condition: the slurry concentration was 3%, modifier temperature was 70℃, modified time was 50min, the amount of modifier was 8‰wt(CaCO3), when the activation of the modified heavy calcium carbonate can up to be 91.2%. It is found that the sodium dodecyl benzene sulfonate have effectively covered on the surface of heavy calcium carbonate by the IR infrared test of the modified heavy calcium carbonate. Obviously, the improvement of the performance of heavy calcium carbonate is the result of modification.