I. Process introduction
First dissolve bischofite, remove the impurities through purification, take liquid supernatant through precipitation and react with precipitant to generate basic magnesium carbonate precipitation, then through rinsing and dehydrating, produce basic magnesium carbonate wet cake. According to different product varieties, produce magnesium oxide products of different grades under different temperature conditions through heat treatment. Basic magnesium carbonate mother liquid reacts with hydroxide of alkaline-earth metals, volatilize ammonia. Through absorption and reacting with carbon dioxide generated from magnesium oxide calcination procedure, produce ammonium carbonate solution. The effluent generated during ammonia steaming is further disposed to achieve calcium chloride product.
II. Technical Advancement
Magnesium conversion rate is above 85%, the product is main content is within 98.6%-99.4%. Product quality is in conformity with the requirements of medical (food), electronic, electrician, metallurgy, aerospace, high molecular and other fields.
III. Market Prospect
Magnesium oxide is important inorganic chemical product, which is widely applied in rubber, medicine, food, electronic, refractory material, metallurgy, national defence, aerospace, chemical industry, environmental protection and other fields, playing a very important role in the construction of national economy. In recent years, domestic and foreign market has growing demand for magnesium oxide, appearing the situation of demand exceeding supply. The market prospect is very broad.
IV. Technical Sources
Autonomous research and development, and industrialization has been realized in Shandong, Qinghai and other places.
V. Product Quality
Table 1:
|
Indicator Name |
Standard |
Indicator Name |
Standard |
|
MgO/% |
98.2 |
Sulfate/% ≤ |
0.1 |
|
CaO/% ≤ |
0.25 |
Fe/% ≤ |
0.0005 |
|
Insoluble matter in acid/% ≤ |
0.05 |
Heavy metal (Pb) ppm≤ |
20 |
|
Cl-/% ≤ |
0.08 |
Bulk density g/ml |
0.25 -0.6 |
Table 2:
|
Indicator Name |
Standard |
Indicator Name |
Standard |
|
MgO/% |
99.5 |
sulfate/% ≤ |
0.1 |
|
CaO/% ≤ |
0.15 |
Fe/% ≤ |
0.005 |
|
Insoluble matter in acid/% ≤ |
0.05 |
Heavy metal (Pb) ppm≤ |
10 |
|
Cl-/% ≤ |
0.08 |
Bulk density g/ml |
0.35 |
VI. Investment Scale
According to annual production of high-purity magnesium oxide 1000t, equipment investment is 3.5 million Yuan.
VII. Environmental Protection
Traditional magnesium carbonate synthesis process. Production process will generate a good deal of ammonia-containing waste water, causing environmental pollution, which has become the burden of production enterprises. Shandong Qingzhou Hongji Chemical Industry Co., Ltd. was forced to stop production in 2006 because mother liquid discharge caused environmental pollution. In order to solve this problem, this process is supported with comprehensive utilization technology and device of magnesium carbonate mother liquid. The mother liquid and washing water generated during production is used in recovery of ammonia (ammonia water) for cycle use, thoroughly eliminating environmental pollution caused by mother liquid and washing water discharge.
In addition, calcine basic magnesium carbonate into magnesium oxide, a good deal of carbon dioxide gas discharge during the process, this is not allowed in the current environmental protection policy. In order to solve this problem, this process also developed the matched carbon dioxide recovery process, and made carbon dioxide react with the recovered ammonia water, transformed into ammonium carbonate solution, and recycle in precipitation reaction of basic magnesium carbonate.
VIII. Economic Benefits
Product production cost is about 6,500 Yuan/T, factory price is 12,000-30,000 Yuan/T, having high additional value, extremely big profit space and significant economic benefits.
IX. Form of Cooperation
Technical transfer. Taking responsibility for process flow design, supporting equipment of standard equipment, non-standard equipment manufacture design, equipment is plane layout design, equipment installation design, pipe network design, equipment installation guidance, equipment commissioning, production commissioning, training for production engineers, analysis staff and technicians, process operation specifications, raw material and product analysis method, and preparation of intermediate control analysis method; ensuring output, yield and quality to reach the standard; and undertaking turn-key projects.