( 中南大學(xué) 冶金科學(xué)與工程學(xué)院， 長沙 410083)
摘 要: 研究了碳酸氫銨-氨水熱解法制備輕質(zhì)氧化鎂的工藝條件， 考察了原料Mg2+濃度、 反應(yīng)溫度、 Mg2+與NH3t當(dāng)量比、 NH3與NH4HCO3摩爾比和預(yù)氨化pH值對堿式碳酸鎂的過濾性能、 沉鎂效率和碳酸氫銨消耗量的影響，并探討了煅燒溫度、 煅燒時間、 升溫速度對輕質(zhì)氧化鎂視比容的影響。 最佳工藝參數(shù)為： 原料Mg2+濃度2.5 mol/L、 反應(yīng)溫度50 ℃、 當(dāng)量比115%、摩爾比1.35、 預(yù)氨化pH值7.8~7.9、 煅燒溫度800 ℃、 煅燒時間60 min、 升溫速度6 ℃/min。 在最佳工藝條件下， 沉鎂效率為82%， 生產(chǎn)1 t輕質(zhì)氧化鎂消耗碳酸氫銨量降到了1.76 t左右， 產(chǎn)品質(zhì)量優(yōu)于HG1-324-77特級標(biāo)準(zhǔn)。 該工藝可作為開發(fā)鹽湖水氯鎂石資源的有效途徑。
關(guān)鍵字: 水氯鎂石； 碳酸氫銨； 氨水； 堿式碳酸鎂； 輕質(zhì)氧化鎂
CHEN Qi-yuan, DENG Xin-rong
（ College of Metallurgical Sciences and Engineering,Central South University, Changsha 410083, China）
Abstract: The technological parameters of the productive process of light magnesium oxide by ammonium bicarbonate-ammonia pyrogenation technology had been studied. The effects of raw material Mg2+concentration, reaction temperature, equivalent ratio, mol-ratio and aminated pH on the filtration capability of basic magnesium carbonate, yield of Mg2+ and the consumption of NH4HCO3 were investigated, and the effects of calcination temperature, time and rising speed of the temperature on the apparent gravity of light magnesium oxide were also investigated. The optimal technological parameters were: content of Mg2+ in raw material 2.5 mol/L, reaction temperature 50 ℃, equivalent ratio 115%, mol-ratio 1.35, aminated pH 7.8-7.9, calcination temperature 800 ℃, calcination time 60 min, rising speed of temperature 6 ℃/min. Under the optimal technological parameters, the results achieve yield of Mg2+about 82% and the consumption of NH4HCO3 for each ton light magnesium oxide reduces to 1.76 t in the process and the product has met the superfine-class standard of HG1-324-77. This process may be one of the effective routes to exploit the resources of saline bischofite.
Key words: bischofite； ammonium bicarbonate； ammonia； basic magnesium carbonate； light magnesium oxide
