Jinpeng Group – BMSC (Basic Magnesium Sulfate Cementitious) 517 New Sulfate MGO Cementitious Development Situation Updates

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​Inorganic cementitious materials using calcium salts as hydration products are widely used in civil engineering projects such as buildings, roads, bridges, tunnels, airports, and dams. Common calcium cementitious materials include lime, gypsum, Portland cement, Aluminate cement, and sulfoaluminate cement. Calcareous cementitious materials have significantly contributed to modern civil engineering development.

Like calcium cementitious materials, magnesium cementitious materials are another type of inorganic cementitious material that uses magnesium salts as hydration products. Common magnesium cementitious materials include magnesium oxychloride and magnesium oxysulfide.

Magnesium, the fourth most abundant element in the earth's composition, accounts for 12.7% of the total. This abundance makes it a more readily available raw material for cementitious materials compared to calcium. Despite this advantage, the widespread use of magnesium cementitious materials in civil engineering has been limited for various reasons.

 

With substantial financial support from the "Hundred Talents Plan" of the Chinese Academy of Sciences, we synthesized a new pure phase sample of basic magnesium sulfate. Through cooperation between scientific research institutions in China and Germany, we successfully analyzed its chemical composition and crystal structure. The phase is abbreviated as 5·1·7 phase. The crystal structure data of 5·1·7 has been entered into the International Inorganic Crystal Structure Database (ICSD), card number CSD-No.425847.

Using advanced testing methods, we found that the 5·1·7 phase has completely different properties than the 3·1·8 phase, the hydration product of traditional magnesium oxysulfide cement. Its solubility in water is very low and can only dissolve 0.034g/100g water, which is about 1/1241 of the solubility of the 3·1·8 phase.

At the same time, it is only 1/2359 of the solubility of the 5·1·8 phase of the main hydration product of magnesium oxychloride cement, which is the same as Portland cement.

The solubility data of CSH gel and ettringite, the main hydration products of sulfoaluminate cement, are at a very low order of magnitude. To distinguish it from the traditional magnesium oxysulfate cement, according to the rules of cement naming, this new type of magnesium oxysulfate cement with 5·1·7 phase as the main hydration product is named basic magnesium sulfate cement. This cement has the advantages of muscular, high strength, low alkali, water resistance, no moisture absorption and halogen return, good high-temperature resistance, and non-corrosive steel bars. It is suitable for making structural, insulation, and decorative materials in the construction industry. The theoretical innovation of basic magnesium sulfate cement has attracted the favor of the business community and is being steadily promoted and implemented.

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Through an in-depth analysis of the cement's characteristics, a series of products for further application have been developed: plastering spray mortar, repair mortar, waterproof mortar, etc., which have passed the testing of relevant national departments.
Based on its excellent water resistance, fire resistance, low thermal conductivity, and other characteristics, it is used in various cement products and structures.

It can replace wood and be used as packaging materials in the equipment manufacturing industry, supports and guards for coal industry mines, skeletons of granaries and greenhouses in rural areas, beautiful guardrails and artistic landscapes in municipal projects, and even partitions in wood products, etc.; It can replace the wall materials used in modern buildings to produce more efficient and insulated building energy-saving walls and roofs, and various more environmentally friendly decorative materials, such as fireproof boards that are both fireproof and bending-resistant, and their toughness is comparable to wood products; It can produce large-format imitation stone and imitation wood building decoration materials; it can be used in new building structures, such as maritime engineering, military engineering, bridges and dams, etc.; it can also be used for rapid repair of airport runways, rapid repair of waterproofing projects, etc. It is fully aligned with the circular economy.
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