What Is Magnesium Hydroxide?

Magnesium hydroxide, white amorphous powder. Also known as caustic magnesite, light burned magnesia, etc., the suspension of magnesium hydroxide in water is called magnesium hydroxide emulsion, referred to as magnesium milk, and the English name is Magnesium hydroxide. Magnesium hydroxide is a colorless hexagonal prism crystal or white powder. It is difficult to dissolve in water and alcohol, and it is soluble in dilute acid and ammonium salt solution. The aqueous solution is weakly alkaline. The solubility in water is very small, but the water-soluble part is completely ionized. The concentration of the saturated aqueous solution was 1.9 mg / liter (18 ° C). Heating to 350 ° C loses water to form magnesium oxide. Natural mineral brucite, magnesium hydroxide. Can be used for sugar and magnesium oxide. Because magnesium hydroxide is rich in nature, and its chemical properties are similar to aluminum, users have begun to use magnesium hydroxide instead of aluminum chloride for deodorant products. Used as analytical reagents and also in the pharmaceutical industry.

1. Magnesium hydroxide is an excellent flame retardant for plastic and rubber products. In terms of environmental protection, it can be used as a flue gas desulfurizer and can replace caustic soda and lime as a neutralizer for acid-containing wastewater. It is also used as an oil additive to prevent corrosion and desulfurization. In addition, it can also be used in the electronics industry, medicine, sugar refining, as a thermal insulation material, and other magnesium salt products.

2. Magnesium hydroxide has excellent buffering performance, reactivity, adsorptive power, and thermal decomposition performance. It can be used as a chemical material and intermediate, and a green environmentally friendly flame retardant and additive for rubber, plastic, and fiber And resin and other polymer materials industries. In the field of environmental protection, magnesium hydroxide is mainly used as a flame retardant, an acid wastewater treatment agent, a heavy metal removal agent, and a flue gas desulfurization agent. ^[2]

(A): Industry often uses seawater to react with cheap calcium hydroxide solution (lime milk) to obtain magnesium hydroxide precipitation.

The brine-lime method is a method in which brine that has been previously purified and refined and lime that has been digested and slag-treated is prepared.

Magnesium hydroxide is hardly soluble in water and belongs to a weak base, but slightly to the eyes, respiratory system and skin

Rumor: Magnesium hydroxide cannot react with carbon dioxide.

Refutation: Magnesium hydroxide can react with carbon dioxide. The following is a description of the literature.

Dolomite is used to make light magnesium carbonate. Dolomite is digested to form a suspension of calcium hydroxide and magnesium hydroxide . The carbonization reaction is carried out using a kiln gas containing carbon dioxide to generate calcium carbonate and magnesium bicarbonate. Those with different solubility reach the separation of calcium and magnesium, and then pyrolyze the magnesium bicarbonate remaining in the solution.

The precipitation process of hydrated magnesium carbonate from the reaction crystallization of magnesium hydroxide suspension and carbon dioxide was studied experimentally, and the influence of different operating conditions on the particle size distribution characteristics of the final product was discussed. The results show that the crystalline products precipitated are all magnesium carbonate trihydrate (MgCO ₃ · 3H ₂ O). ^[3]

first aid:

Inhalation: If inhaled, remove patient to fresh air.

Skin contact: Remove contaminated clothing and rinse skin thoroughly with soap and water. Seek medical attention if you feel unwell.

Eye contact: Separate the eyelids and rinse with running water or saline. Seek medical attention immediately.

Ingestion: Rinse mouth and do not induce vomiting. Seek medical attention immediately.

Advice for protecting rescuers: Move patients to a safe place. Consult a doctor. Show this chemical safety data sheet to the doctor at the scene. ^[2]

Extinguishing media: Extinguish with water spray, dry powder, foam or carbon dioxide. Avoid using DC water to extinguish the fire. DC water may cause the splash of flammable liquid and spread the fire.

Fire Fighting Precautions and Protective Measures: Firefighters must wear portable breathing apparatus, full-body fire protection clothing, and extinguish fire in the upwind direction. Move the container from the fire to the open space as much as possible. Containers in the fire must be evacuated immediately if they have changed colour or made a sound from a safety pressure relief device. Isolate the scene of the accident and prohibit unrelated personnel from entering. Contain and handle fire fighting water to prevent environmental pollution. ^[2]

Protective measures for workers, protective equipment and emergency procedures: Emergency handlers are recommended to wear portable breathing apparatus, antistatic clothing, and rubber oil-resistant gloves. Do not touch or cross spillage. All equipment used during work should be grounded. Cut off the source of the leak if possible. Eliminate all ignition sources. The warning area is defined according to the area affected by liquid flow, vapor or dust diffusion, and irrelevant personnel are evacuated from the crosswind and upwind to the safe area.

Environmental protection measures: contain leaks and avoid polluting the environment. Prevent spills from entering sewers, surface water and groundwater.

Methods and materials for containment and cleaning up of spilled chemicals:

Small leaks: Collect leaking liquid in sealable containers if possible. Absorb with sand, activated carbon or other inert materials and transfer to a safe place. Do not rush into the sewer.

Large spills: build dikes or dig pits for containment. Close the drainage pipe. Cover with foam to suppress evaporation. Use explosion-proof pump to transfer to tanker or special collector, recycle or transport to waste disposal place for disposal. ^[4]

Operators should be specially trained and strictly abide by the operating procedures. Operation and disposal should be carried out in a place with local ventilation or full ventilation ventilation facilities. Avoid contact with eyes and skin. Avoid breathing steam. Away from fire and heat sources, smoking is strictly prohibited in the workplace. Use explosion-proof ventilation systems and equipment. If canning is required, the flow rate should be controlled and a grounding device should be provided to prevent static electricity accumulation. Avoid contact with incompatible materials such as oxidants. Handle with care when handling to prevent damage to packaging and containers. Empty containers may be harmful residues. Wash hands after use and do not eat or drink in the workplace. Equipped with the corresponding variety and quantity of fire fighting equipment and leakage emergency treatment equipment.

Store in a cool, ventilated warehouse. The storage temperature should not exceed 37 ° C. It should be stored separately from oxidants and edible chemicals. Keep container tightly closed. Keep away from fire and heat sources. The warehouse must be equipped with lightning protection equipment. The exhaust system shall be provided with a grounding device to conduct static electricity. Adopt explosion-proof lighting and ventilation settings. Never use spark-prone equipment and tools. ^{[2] The} storage area should be equipped with spill emergency treatment equipment and suitable containment materials.