Industrial-grade 52% 97% Calcium bromide CAS 7789-41-5

What is Calcium Bromide? How does it work?

Calcium bromide (also known as calcium dibromide, calcium bromide, calcium bromide dihydrate, etc.), with the chemical formula CaBr2, a molecular weight of 199.89, CAS number 7789-41-5, EINECS 232-164-6, UNII 87CN64IMSG, and InChIKey WGEFGECEFUFIQW-UHFFFAOYSA-L, is an ionic bromide salt composed of calcium ions (Ca²⁺) and two bromide ions (Br⁻), belonging to the class of inorganic metal bromides. It is an important industrial bromine chemical: a white, hygroscopic crystalline powder or granules, odorless with a sharp, salty taste, melting point approximately 730℃, density approximately 3.35 g/cm³, extremely soluble in water (approximately 58.8% solubility at 20℃, approximately 1420 g/L at 30℃), its aqueous solution is neutral or slightly alkaline, and can be formulated into high-density clear brine with a specific gravity exceeding 1.7. Due to its high solubility, high density, strong hygroscopicity, and the flame-retardant, corrosion-preventive, and mercury-oxidizing properties of bromide ions, industrial-grade calcium bromide is widely used in oil and gas, power generation and environmental protection, flame retardant fire protection, refrigeration, imaging, wood, textiles, water treatment, mining, and chemical industries—its largest application is as a drilling, completion, workover, and kill fluid in oil fields (accounting for approximately 52-54%, specific gravity >1.7). It is also a traditional raw material for mercury emission control agents in power plants and incinerators, components of flame-retardant and fire-resistant materials, and for freezing brine and photographic materials.

Basic identification information : Chemical formula CaBr2 (Br2Ca); Molecular weight 199.89; CAS number 7789-41-5; EINECS 232-164-6; UNII 87CN64IMSG; InChIKey WGEFGECEFUFIQW-UHFFFAOYSA-L; IUPAC name: calcium dibromide; Synonyms: calcium bromide, calcium dibromide, calcium bromide hydrate, calcium bromide (CaBr2), etc.

Structurally , calcium bromide is a typical ionic compound, consisting of calcium cations and bromide anions linked by ionic bonds. In the crystal lattice, calcium ions coordinate with multiple bromide ions to form orthorhombic or rhombohedral crystals. The anhydrous form has the chemical formula CaBr2, and commercially available forms are usually anhydrous or dihydrates.

Physically , calcium bromide is a white crystalline powder, granules, or orthorhombic crystal, odorless with a sharp, salty taste; melting point approximately 730℃ (anhydrous); boiling point approximately 806-812℃ (decomposes and releases hydrogen bromide fumes when heated to approximately 810℃); density approximately 3.35-3.38 g/cm³ (solid, specific gravity 3.353@25℃); extremely soluble in water (0℃ 55.5%, 20℃ 58.8%, 40℃ 68.1%, 60℃ 73.5%, 100℃ 75%, 30℃ approximately 1420 g/L), also soluble in ethanol and acetone; aqueous solution is neutral or slightly alkaline; strongly hygroscopic and deliquescent, absorbing moisture and gradually turning yellow when exposed to air; chemically stable, but decomposes at high temperatures to produce toxic hydrogen bromide.

Chemically , calcium bromide is a strong electrolyte ionic salt: it completely ionizes in water into calcium ions and bromide ions, resulting in good electrical conductivity. Bromide ions (Br⁻) are active halide anions that can participate in displacement, redox, and complexation reactions. During combustion, they can capture free radicals, exert a gas-phase flame-retardant effect, and also form oxidative complexes with mercury to promote mercury removal. Calcium and bromide ions give the solution high density and osmotic pressure, and their colligative properties significantly lower the freezing point of the aqueous solution. Its strong hygroscopicity comes from the strong affinity of calcium ions for water molecules, making it suitable as a dehydrating agent. Bromine has antibacterial and preservative activity, inhibiting microbial growth. It is stable under alkaline conditions and releases hydrogen bromide upon contact with strong acids.

Why does calcium bromide play these roles in industry? Its mechanism of action mainly includes the following:

High-density brine mechanism : The extremely high water solubility of calcium bromide (approximately 58.8% at 20℃) and its large ionic mass allow its aqueous solution to have a density exceeding 1.7 g/cm³, and it is free of solid phase, clear and transparent; the hydrostatic pressure generated by high-density brine can balance formation pressure, and it is used to protect the wellbore and prevent blowouts and formation damage during drilling, completion, workover and well control. This is the basis for its use as oilfield brine and mining gravity separation fluid.

Freezing point depression mechanism : Calcium bromide completely ionizes into ions in water, which significantly lowers the freezing point of the aqueous solution according to colligative properties. It can be used to prepare low freezing point brine and refrigeration mixtures for low-temperature heat transfer and freezing, while the solution has low viscosity and good heat transfer efficiency.

Bromine free radical flame retardant mechanism : During combustion, bromine free radicals released by calcium bromide enter the gas phase, capture active free radicals such as H· and OH· in the combustion chain reaction, interrupt the combustion chain, dilute the combustible gas and form a heat insulation and oxygen barrier layer, thus playing a role in flame retardancy and fire extinguishing. This is the core function of bromine-based flame retardant and fire extinguishing materials.

Moisture absorption and dehydration mechanism : Calcium ions have a strong affinity for water molecules, giving calcium bromide strong hygroscopic and deliquescent properties. It can absorb bound moisture from gases, liquids or systems and be used as a desiccant and dehydrating agent. It can also absorb moisture from road dust to suppress dust.

Mercury oxidation and complexation mechanism : Calcium bromide promotes the oxidation of elemental mercury to divalent mercury ions in the aqueous phase and forms stable complexes with them, so that mercury in the flue gas is transferred from the gaseous state to the aqueous or solid phase, which is convenient for dust removal. This is the core function of mercury emission control in power plants and incinerators.

Bromine preservation mechanism : Bromine ions have broad-spectrum antibacterial activity and can inhibit the growth of bacteria, fungi and wood decay fungi. Therefore, calcium bromide can be used as a wood preservative and a bactericidal component for water treatment. It has good solubility and strong permeability, and can penetrate deep into wood and water to exert a long-lasting preservation effect.

 All Uses of Industrial-Grade Calcium Bromide

1. Oilfield drilling, completion, workover, and kill fluids (oil and gas industry)

Corresponding products: drilling fluid, completion fluid, workover fluid, kill fluid, packer fluid, gravel packing fluid, high-density brine, solids-free brine systems, etc.

Why it can be used for this purpose: Calcium bromide can be used to prepare high-density clear brine with a specific gravity of over 1.7. As a solid-free brine system, it can control wellbore pressure, balance formation pressure, and prevent blowouts and well kicks. At the same time, it contains no solid particles, causes little damage to oil and gas reservoirs, and is easy to recover and recycle. It is a mainstay brine material for drilling, completion, and workover operations in oil fields (accounting for about 52-54% of calcium bromide usage), and it is also classified as a petroleum production and processing aid and density regulator in industrial applications.

2. Mercury emission control agents for power plants and incinerators (power/environmental protection industry)

Corresponding products: Mercury removal additives for coal-fired power plants, mercury oxidants for flue gas, mercury emission control agents for incinerators, mercury removal aids, desulfurization and mercury removal synergistic agents, flue gas treatment chemicals, etc.

Why it can be used in this way: When calcium bromide is injected into coal-fired flue gas, it promotes the oxidation of elemental mercury to divalent mercury and forms a stable complex, so that mercury is removed from the flue gas along with dust removal and desulfurization devices, significantly reducing mercury emissions. This is an important new application for mercury emission control in power plants and incinerators, and it is also an increasingly popular environmental application of calcium bromide.

3. Flame retardants and fireproof materials (flame retardant/building materials industry)

Corresponding products: flame-retardant plastics, flame-retardant rubber, fire-retardant coatings, flame-retardant fabrics, flame-retardant foams, flame-retardant sheets, flame-retardant wires and cables, flame-retardant adhesives, etc.

Why it can be used for this purpose: Calcium bromide is added to flame retardant formulations as a bromine source. When it burns, it releases bromine free radicals, interrupting the combustion chain reaction and inhibiting flame propagation. When used with antimony-based synergists, it can enhance flame retardant efficiency. As a component of flame retardant blends, it is used in flame retardant products such as plastics, rubber, coatings, and fabrics.

4. Firefighting materials (fire protection industry)

Corresponding products: fire extinguishing agents, fire extinguishing compositions, fire extinguishing agents, special fire extinguishing materials, fire extinguishing powders, fire extinguishing liquids, etc.

Why can it be used for this purpose? Calcium bromide, as a component of fire extinguishing compositions, releases bromine free radicals when heated, interrupting the combustion chain and diluting combustible gases. It works in conjunction with other fire extinguishing ingredients to exert a rapid fire extinguishing effect and is a bromine-based functional component in fire extinguishing material formulations.

5. Chilled brine and refrigeration mixture (refrigeration/chemical industry)

Corresponding products: frozen brine, refrigeration mixtures, cryogenic circulating fluids, cold storage refrigerants, ice-making brine, chemical refrigerants, cryogenic heat transfer media, etc.

Why it can be used for this purpose: Calcium bromide completely ionizes in water, significantly lowering the freezing point of aqueous solutions. It can be used to prepare low-temperature freezing brine and refrigeration mixtures for use in cold storage, ice making, and low-temperature chemical processes. The solution has low viscosity, high heat transfer efficiency, and no controllable corrosion issues, making it one of the traditional refrigeration brine materials.

6. Photographic materials (imaging industry)

Corresponding products: photographic dry plates, photosensitive paper, photographic emulsions, photographic films, printing paper, photosensitive materials, imaging chemicals, etc.

Why it can be used for this purpose: Calcium bromide is used as a bromine source to prepare silver bromide photosensitive emulsion. Its bromide ions combine with silver ions to form photosensitive silver bromide microcrystals, which are traditional raw materials for the manufacture of photographic plates, photosensitive paper and photosensitive film.

7. Wood preservatives (wood industry)

Corresponding products: railway sleepers, utility poles, outdoor wooden structures, wooden fences, boardwalks, log cabin materials, wooden gardening supplies, preservative-treated timber, etc.

Why it can be used for this purpose: The bromide ions in calcium bromide have antibacterial and preservative activities, which can inhibit wood decay fungi and insect pests. As a wood preservative, it penetrates into the wood fibers to exert a long-lasting preservative effect and extend the life of outdoor and load-bearing wood products.

8. Textile sizing agents (textile industry)

Corresponding products: warp sizing agents, weaving sizing agents, textile sizing solutions, yarn treatment agents, sizing auxiliaries, fabric finishing agents, etc.

Why it can be used for this purpose: Calcium bromide is added to the sizing compound system as a component of the sizing compound to improve the sizing solution penetration and yarn strength, reduce warp yarn breakage, improve weaving efficiency and fabric quality, and is an auxiliary component in textile sizing formulations.

9. Water treatment agents (water treatment industry)

Corresponding products: industrial circulating water disinfectant, cooling water treatment agent, swimming pool disinfection aid, drinking water treatment agent, oilfield reinjection water treatment agent, wastewater treatment chemicals, etc.

Why it can be used for this purpose: Calcium bromide is used as a bromine source and bactericidal component in water treatment. Bromine ions release active bromine in the water, inhibiting the growth of bacteria and algae. When used in conjunction with oxidants, it can maintain a long-lasting bactericidal effect. It is suitable for systems such as circulating cooling water, oilfield reinjection water, and wastewater treatment.

10. Remediation solutions for contaminated soil and groundwater (environmental protection industry)

Corresponding products: DNAPL (Dense Non-Aqueous Phase Liquid) pollution remediation solution, contaminated soil treatment agent, groundwater remediation brine, density-adjusting remediation solution, site remediation chemicals, etc.

Why it can be used for this purpose: Calcium bromide high-density brine can be used as a gravity displacement and density conditioning fluid. It can be injected into contaminated formations to move heavy non-aqueous liquids (such as chlorinated solvents) and be extracted for treatment. At the same time, its density characteristics facilitate the directional flow of remediation fluid in the contaminated area, which is an emerging application for contaminated site remediation.

11. Mineral density conditioning and gravity separation fluids (mining/mineral processing industry)

Corresponding products: heavy media mineral processing solution, gravity separation solution, density conditioning solution, ore separation media, coal washing heavy liquid, mineral separation brine, etc.

Why it can be used for this purpose: High-density aqueous solution of calcium bromide is used as a heavy medium and density regulating liquid. It utilizes the density difference between ore and gangue to achieve gravity separation. Its characteristics of no solid phase, adjustable density, and recyclability make it suitable for mineral processing and mineral separation processes. It is also a density regulator in the industrial application category.

12. Road treatment agents (road maintenance/municipal industry)

Corresponding products: road dust suppressants, road surface stabilizers, soil road maintenance agents, road snow melting aids, dust control agents, construction road treatment fluids, etc.

Why it can be used for this purpose: Calcium bromide's strong hygroscopic properties allow it to absorb moisture from the air to keep the road surface moist and suppress dust. As a road treatment agent, it can be sprayed on dirt roads and construction roads to reduce dust. Its moisture-absorbing and water-retaining properties can also help melt snow and prevent ice in winter.

13. Chemical intermediates and dehydrating agents (chemical industry)

Corresponding products: ammonium bromide, other metal bromides, hydrogen bromide solution, bromine chemical intermediates, dehydrating desiccants, drying chemicals, fine chemical raw materials, etc.

Why can it be used for this purpose? Calcium bromide is an intermediate raw material for the production of ammonium bromide and other metal bromides. It provides a bromine source through metathesis reaction. Its strong hygroscopicity also makes it suitable as a dehydrating agent to absorb moisture from gases or liquids. It is a multifunctional bromine chemical in chemical production.

Summarize

Industrial-grade calcium bromide (CAS 7789-41-5) is an ionic bromide salt composed of calcium and bromine. Its core strengths lie in its extremely high water solubility, high-density brine capacity, strong hygroscopicity, and the flame-retardant, anti-corrosion, and mercury-oxidizing properties of bromide ions. It serves industries such as oil and gas, power generation and environmental protection, flame retardant fire protection, refrigeration, imaging, wood, textiles, water treatment, mining, and chemicals. Its primary application is in high-density brine (approximately 52-54%) for oilfield drilling, well completion, well workover, and well control. It is also used as a mercury emission control agent in power plants and incinerators, a flame-retardant component, a freezing brine, a raw material for photographic materials, a wood preservative, a textile sizing agent, a water treatment agent, and a chemical intermediate. Understanding its ionic structure of "calcium ion + two bromide ions" and the chemical activity of bromide ions explains why it can simultaneously adjust density, lower freezing point, provide flame retardancy, remove mercury, and prevent corrosion—this is precisely why it spans more than ten industrial sub-applications and becomes a versatile industrial bromine chemical.