Barium sulfate 1

Barium Sulfate CAS No.:7727‑43‑7

Physical & Chemical Properties Melting point: 1580 °C Boiling point: Decomposes at 1580 °C Density: 4.5 Bulk density: 500 kg/m³ Storage condition: No special temperature restrictions for storage. Solubility in water: Insoluble Form: Powder Color: White to yellow Specific gravity:4.5 Odor: Odorless fine white powder pH value: 3.5‑10.0 (100 g/L, H₂O, 20 °C, suspension) Water solubility: 0.0022 g/L (50 °C) Thermal conductivity: 1.674 W/(m·K) (crystal) Specific heat capacity Cp (crystal): 0.44 J/(g·K) at 25 °C Crystal structure: Barite Merck index:14,994 Ksp (pKsp):9.97 Space group: Pnma Lattice parameters: a=0.8909 nm, b=0.5467 nm, c=0.7188 nm；α=90°, β=90°, γ=90° Dielectric constant:11.4 (16.0 °C) Occupational exposure note: Wear proper dust‑proof protection during handling. Stability: Stable. Cosmetic function: Colorant, opacifying agent InChI: 1S/Ba.H2O4S/c;1‑5(2,3)4/h;(H2,1,2,3,4)/q+2;/p‑2 InChI Key: TZCXTZWJZNENPQ‑UHFFFAOYSA‑L SMILES: [Ba++].[O‑]S([O‑])(=O)=O LogP:‑1.031(estimated) 

Chemical Traits Also known as barite, molecular formula BaSO₄, molecular weight 233.40. It is colorless or white orthorhombic crystal. Specific gravity 4.5 (15℃), melting point 1580℃, refractive index 1.637. It transforms into monoclinic crystal when heated to 1149℃ with refractive index 1.649. It is nearly insoluble in water, slightly soluble in hot concentrated sulfuric acid. It can convert into barium carbonate in alkali‑metal carbonate solution, and insoluble in most other acids and alkalis. It exists naturally as barite mineral. When co‑heated with coal powder at 800℃, it can be reduced into soluble barium sulfide. 

Application 1. Petroleum & natural gas industry: weighting agent for drilling mud. Raw material for manufacturing barium metal and various barium compounds. 2. Rubber, plastic, coating, paint, ink, paper‑making and textile industries: used as filler and raw material. It can serve as surface coating agent for printing‑out paper and coated paper, and sizing agent for textile processing. 3. Glass & ceramic industry: acting as clarifying agent for glass products to eliminate foam and improve gloss. Applied in enamel, pigment and ceramic manufacturing. 4. Other fields: raw material for barium‑based lubricating grease, oil refining, beet‑sugar processing and artificial silk production; radiation‑proof wall material; raw material for producing other barium salts.

Manufacturing Methods

Method 1: Glauber‑salt‑black‑ash process Reaction equations: BaSO₄ +4C → BaS +4CO ↑ BaS + Na₂SO₄ → BaSO₄ ↓ + Na₂S Procedure: Clarify leachate generated from barite and coal reaction to prepare 14%‑17% barium sulfide solution and heat to 80℃. Prepare glauber salt solution (calcium and magnesium removed) to 22%‑25% concentration and heat to 90℃. Add barium sulfide solution into glauber‑salt solution under stirring, keep reaction temperature at 90℃, reach equivalent reaction endpoint. Filter precipitate, wash with water and pickling, adjust pH to 5‑6 with sulfuric acid, then filter, dry and pulverize to obtain precipitated barium sulfate.  Method 2: Bittern comprehensive utilization process Reaction equation: BaCl₂ + Na₂SO₄ → BaSO₄ ↓ + 2NaCl Procedure: React barium‑containing brine with glauber salt, followed by acid boiling, water washing, dehydration and drying to get finished barium sulfate. 

Mining & beneficiation Natural barite ore is mined by open‑pit for eluvial deposits, and underground mining for primary ore. Beneficiation approaches include hand sorting, gravity separation, magnetic separation and flotation.

Transportation & Storage Store in ventilated, cool and dry place. Keep separated from aluminum and potassium materials.