类球状纳米碳酸钙的制备及改性工艺条件研究

研究了以D-葡萄糖酸钠作为晶形控制剂、石灰乳液碳化法制备类球状纳米碳酸钙的工艺条件,以及十二烷基磺酸钠为改性剂的湿法改性工艺条件。XRD,TEM等表征结果表明:在温度50℃、搅拌转速800 r/min、晶形控制剂质量分数1.5%、Ca(OH)2初始质量分数7%、CO2气体流速60 mL/min时,制备的纳米碳酸钙样品属于方解石型六方晶系,形貌类似球状,粒径均匀(50~100 nm)。吸油量测定结果表明:在改性剂质量分数3.5%、改性温度70℃、改性时间50 min时,改性所得样品吸油量(以100 g计)约44 mL,符合国家工业碳酸钙行业标准(GB/T 19281—2003《碳酸钙分析方法》)一等品的要求[吸油量(以100 g计)小于60 mL]。

Study on synthesis and modification of spherical-like nanometer calcium carbonate

The process conditions to prepare spherical-like calcium carbonate by carbonization method from lime slurry and modification conditions of wet process using sodium dodecyl sulfate as modifying agent are studied using D-sodium gluconateas as crystal controlling agent.The XRD and TEM results show that the as-prepared nanometer calcium carbonate is calcite with hexagonal crystal system and spherical-like with uniform diameter of about 50～ 100 nm when the temperature is 50 ℃,stirring speed is 800 r/min,crystal controlling agent mass fraction is 1.5％,Ca （OH） 2 initial mass fraction is 7％,CO2 gas flow rate is 60 mL/min.The results of oil absorption show that when the mass fraction of modification agent is 3.5％,the temperature of modification is 70 ℃,the modification time is 50 min,the oil absorption of spherical-like nanometer calcium carbonate reaches minimum of about 44 mL/100 g which could meet the first grade standard of national calcium carbonate industry （GB/T 19281-2003） （the oil absorption value should be less than 60 mL/100 g）.