高盐废水资源化
The treatment and utilization of industrial wastewater constitute a crucial aspect of environmental protection efforts that cannot be overlooked. Various environmental issues arising from industrial wastewater emerge in an endless stream,
Among them, the indiscriminate discharge of sodium sulfate wastewater containing salt is one of the cruxes leading to soil compaction, water pollution, and other issues. In order to promote the development of the environmental protection industry,
Huicheng Environmental Protection has developed a technology for the reuse of saline (sodium sulfate) wastewater that meets national emission standards, offers extremely high product added value, and consumes low energy,
It effectively solves the problems of low recovery rates of sulfate ions and sodium ions in existing processes.
This process involves pretreating wastewater containing sodium sulfate to produce refined sodium sulfate solution, which reacts with industrial calcium chloride, calcium chloride wastewater, or calcium chloride waste salt to generate calcium sulfate dihydrate. Through hydrothermal reaction, semi-crystalline whiskers are formed, which are then calcined at high temperatures to produce amorphous whiskers. The by-product sodium chloride solution, after refinement, can provide raw materials for the chlor-alkali process, realizing the resourceful recycling of salt.
No other waste is generated throughout the entire production process, reducing the cost of raw materials. The generated sodium chloride solution is applied in the chlor-alkali industry, while the calcium sulfate crystals produced bring considerable economic benefits. This process effectively reduces wastewater discharge and achieves resource utilization of wastewater.
Calcium sulfate whiskers,also known as gypsum fibers or gypsum whiskers, are fibrous monocrystals of anhydrous calcium sulfate, presenting as white, loose, and fluffy floccules. They are composed of needle-like crystals with a length of approximately 100μm, stacked and intertwined. They have a fluffy and soft texture, resembling cotton wool. They possess a uniform cross-section, complete shape, and well-developed internal structure. Their average aspect ratio is generally between 10 and 80.
Calcium sulfate whiskers possess the fineness of granular fillers, the aspect ratio of short fiber fillers, high temperature resistance, acid and alkali resistance, chemical corrosion resistance, good toughness, excellent electrical insulation, high strength, easy surface treatment, good compatibility with resins, plastics, and rubbers, and can be uniformly dispersed. They exhibit excellent reinforcement and flame retardant properties. Compared to other inorganic whiskers, calcium sulfate whiskers are non-toxic, green, and environmentally friendly materials.
Calcium sulfate whiskers, as a fibrous sub-nanomaterial, are widely used in various fields such as medicine, environmental protection, food, building materials, chemical industry, agriculture, and paper-making. Driven by downstream market demand, the production scale of calcium sulfate whisker enterprises in China has gradually expanded, and the output has increased. Currently, the production capacity of calcium sulfate whiskers in China can reach around 200,000 tons.
其基本性能指标如下：
Basic Performance
Relative molecular mass
average diameter
average length
Average aspect ratio
CaSO4 content
Baidu
melting point
heat resistance
Refractive index
Water solubility (22℃)
relative density
Loose density
tensile strength
Tensile modulus
Mohs hardness
PH value
Loss on ignition % (800℃)
indicator
one hundred and thirty-six point one four
1-8 μm
30-200 μm
10～200
≥98%
≥98%
1450℃
1000℃
one point five eight five
＜1200ppm
0.1-0.4 g/cm3
0.1-0.4 g/cm3
20.5Gpa
178 Gpa
3-4
6-8
≤2
