白云石煅粉制备高纯碱式碳酸镁

     将用氯化铵提钙后的白云石煅粉25克与500mL水及84克硫酸铵混合，加 

热至沸，馏出液体积与氧化镁浸出率的关系如表1所示。 

                    表1馏出液体积与氧化镁浸出率关系 

                  馏出液体积／mL                       M90浸出率／％ 

                        20                            68。7 

                        40                            85．3 

                        60                            93．6 

                        80                            98．9 

      由表1中数据可见，当馏出液体积达到80mL时，样品中的氧化镁己基本浸出完全。将馏出液碳化后作为沉淀剂，在65+3℃的条件下与氧化镁浸出液反应，沉淀经过滤、洗涤、干燥、粉碎后得到碱式产品。其化学分析结果如表2

所示。 

                         表2碱式碳酸镁化学分析结果 

                    分析项目                          分析结果 

                     水分／％ 

                  盐酸不溶物／％ 

                    氧化钙／％                           O．20 

                    氧化镁／％                           42．1 

                   灼烧失重／％                           56．9 

                    氯化物／％ 

                       铁／％ 

                       锰／％ 

                    硫酸盐／％                           O．10 

                   筛余物     15011 m／％ 

                              75um／％ 

                  堆积密度／(g／mL)                       O．10