绿色化利用低品位菱镁矿的实验研究Experimental Study of Ecological Utilization of low-grade Magnesite毕业设计（论文）任务书毕业设计（论文）题目：绿色化利用低品位菱镁矿的实验研究设计（论文）的基本内容：以低品位菱镁矿为原料制备MgCO33H2O和CaCO3，利用X射线衍射、红外光谱和扫描电子显微镜等现代检测手段对产物的成分进行表征，并将MgCO33H2O用于处理含Cu()重金属废水。研究煅烧温度、时间对煅烧产物的影响及反应温度、时间、NH4Cl加入量和液固比对镁溶解的影响，确定最佳工艺条件。研究MgCO33H2O的加入量对Cu()沉淀率的影响。毕业设计（论文）专题部分：题目：绿色化利用低品位菱镁矿的实验研究设计或论文专题的基本内容：研究煅烧温度、时间对煅烧产物的影响及反应温度、时间、NH4Cl加入量和液固比对镁溶解的影响，确定制备MgCO33H2O和CaCO3的最佳工艺条件。利用X射线衍射、红外光谱和扫描电子显微镜等现代检测手段对产物的成分进行表征。研究MgCO33H2O的加入量对Cu()沉淀率的影响。学生接受毕业设计（论文）题目日期第周指导教师签字：2013年月日- 2 - 摘 要随着菱镁矿的不断开采，高品位矿储量越来越少，同时产生了大量低品位菱镁矿等废弃物，如不加以利用，不仅浪费资源，而且污染环境，因此低品位菱镁矿的利用已势在必行。本课题以低品位菱镁矿为原料，研究MgCO33H2O和CaCO3的制备方法，并以MgCO33H2O为沉淀剂，通过化学反应方法处理含Cu()重金属废水，目的在于探索低品位菱镁矿及菱镁矿废弃矿综合利用的新途径；研究一种生产低成本CaCO3和MgCO33H2O的新方法。研究表明，采用1% 的MgCl2作为添加剂，与低品位菱镁矿在650混合煅烧2h，MgCO3的分解率为100%，CaCO3的分解率为4.03%，煅烧产物为CaCO3和MgO，达到钙和镁分离的效果。通过单因素实验确定了由煅烧产物浸出镁的最佳工艺条件为：反应温度为80，反应时间为60min，NH4Cl加入量为1.3倍，液固比为8，采用二次浸出的方法；此时镁溶出率为92%，浸出残渣的主要成分为CaCO3，纯度为89.9%。用含MgCl2滤液与(NH4)2CO3反应制备MgCO33H2O，当反应温度为37，(NH4)2CO3加入量为1.5倍，陈化时间为2h时，MgCO33H2O的产率为55.66%，纯度为96.5%。(NH4)2CO3加入量对MgCO33H2O产率的影响大。在反应温度为常温，反应时间为30min，MgCO33H2O加入量为1倍的条件下，利用MgCO33H2O处理含Cu ()重金属废水时, Cu() 的沉淀率为100%，且MgCO33H2O加入量对Cu()沉淀率的影响不大。通过研究，开发出了一种生产低成本MgCO33H2O和CaCO3的新方法，该方法的确立为低品位菱镁矿的综合利用探索出了一条新的途径。关键词：低品位菱镁矿，浸出，三水合碳酸镁，产率，重金属废水 AbstractWith the continued mining of magnesite, the reserve of high-grade magnesite become fewer and fewer, and a large number of wastes such as low-grade magnesite produced. This will cause not only the wasting of resources, but also a serious environmental problems. Therefore, the comprehensive utilization of low-grade magnesite has been a problem to be solved urgently. In this study, with low-grade magnesite as raw material, the preparation of MgCO33H2O and CaCO3, as well as the chemical treatment of copper-bearing heavy metal wastewater by using MgCO33H2O as precipitant was investigated, which aimed to explore the new ways of utilizing low-grade magnesite and a new method to produce low-cost MgCO33H2O and CaCO3.The results show that with MgCl2 as additive, the low-grade magnesite was calcined. The process conditions are: 650 for 2 h, and the addition of MgCl2 is 1%. Under these conditions, the decomposition rate of MgCO3 is 100%, while the decomposition rate of CaCO3 is 4.03%, the calcined products are mainly composed of CaCO3 and MgO, which has reach the effect of separating calcium and magnesium.The influences of process conditions on the dissolution rate of magnesium were investigated through single-factor experiment. The results showed that the optimal process conditions are: 80 for 60 min, the addition of NH4Cl is 1.3 times, and the ratio of liquid to solid is 8 through two-step leaching, then the dissolution rate of magnesium is 92%, leaching residues are mainly composed of CaCO3 with the purity is 89.9%.Precipitation of MgCO33H2O by the reaction of (NH4)2CO3 with filtered solution which contains MgCl2 was investigated, and the results showed that when reaction temperature is 37, the addition of (NH4)2CO3 is 1.5 times, and aging time is 2h, the yield of MgCO33H2O is 55.66% with the purity is 96.5%, and the addition of (NH4)2CO3 is an important factor effect the yield of MgCO33H2O. The chemical treatment of copper-bearing heavy metal wastewater by using MgCO33H2O as precipitant was investigated, when reaction temperature is room temperature, reaction time is 30 minutes, the addition of MgCO33H2O is 1 time, then the precipitation rate of Cu () obtained is 100 %, and in which the addition of MgCO33H2O has little effect on the precipitation rate of Cu ().A novel method to produce low-cost MgCO33H2O and CaCO3 were developed by this study. The method was established as the comprehensive utilization of low grade magnesite explore a new way.Key words: low-grade magnesite, leaching, trihydrate magnesium carbonate, yield, heavy metal wastewater 目 录毕业设计（论文）任务书i摘 要iiAbstractiii第1章 绪 论11.1菱镁矿资源的低品位化11.2镁化合物生产的研究现状21.2.1氧化镁的分类21.2.2国外氧化镁的生产方法31.2.3国内氧化镁生产方法41.3本研究的目的及意义91.4本研究的主要内容及其优点101.4.1本研究的主要内容101.4.2本研究工艺的优点10第2章 实验原理与方法122.1 实验原理122.1.1 低品位菱镁矿的煅烧122.1.2 煅烧产物中镁的溶出142.1.3镁的沉淀142.1.4 利用产物三水合碳酸镁处理含铜废水142.2 实验工艺流程142.3实验方案152.3.1实验原料152.3.2实验试剂及仪器162.3.3本实验所用的常规检测手段162.4 实验方法172.4.1低品位菱镁矿的煅烧172.4.2煅烧产物中镁的溶出172.4.3 镁的沉淀172.4.4 三水合碳酸镁处理含铜废水17第3章 三水合碳酸镁的制备193.1低品位菱镁矿煅烧方式的选择193.1.1低品位菱镁矿的直接煅烧193.1.2低品位菱镁矿与氯化铵混合焙烧213.1.3低品位菱镁矿与添加剂混合煅烧233.2镁溶出的单因素实验253.2.1反应温度的影响253.2.2 NH4Cl加入量的影响263.2.3反应时间的影响273.2.4液固比的影响283.3镁的沉淀反应303.3.1 MgCO33H2O的表征313.3.2讨论34第4章 三水合碳酸镁的应用实例处理含铜废水38第5章 结论38参考文献39结束语42攻读学位期间参与的研究项目和研究成果