Bismuth and Bismuth Compounds: Main Types and Applications

Bismuth occurs in the Earth’s crust at about the same level as silver. It has a low melting point, high density, and expands when it solidifies. Compared with many heavy metals, bismuth has relatively low toxicity. Its natural radioactivity is also extremely low. For these reasons, bismuth is often described as a “green metal.”

China is the world’s largest bismuth producer and one of its main resource countries. Bismuth products on the market include refined bismuth, bismuth alloys, and compounds such as Bismuth Trioxide, Bismuth Oxychloride, and Bismuth Potassium Citrate. These products are used in low-melting alloys, solders, metal additives, stomach medicines, pigments, cosmetics, and electronic materials.

In recent years, bismuth‑based materials have also been used in catalysts, thermoelectric materials and detectors. They have drawn attention in many fields, such as solar cells, 3D‑printing, flexible sensors and medical imaging.

This article explains the main types, practical uses, and future applications of bismuth metal and bismuth compounds.

Uses of Bismuth

Bismuth has relatively low toxicity compared with lead and many other heavy metals. This has made it useful in lead-free solders, pigments, some metal parts, medicines, and cosmetics.

Bismuth has a low melting point of about 271.4°C. It can form alloys with tin, indium, antimony, cadmium, and other metals. Many of these alloys melt below 200°C. Some melt at much lower temperatures. This makes them useful in low-temperature soldering, thermal safety parts, temporary holding work, and special casting.

Bismuth expands when it becomes solid. The volume increase is about 3.3%. Most metals shrink during solidification. Bismuth can help balance this shrinkage in an alloy. This was important in printing type and precision casting. It is still useful in low-melting molds, lens holding, and parts that need good shape copying.

Bismuth is also dense. Its density is about 9.8 g/cm³. Materials that contain a high amount of bismuth can block or reduce X-rays and gamma rays. This has led to bismuth-filled shielding products and research on medical imaging materials.

Its electrical and optical properties open another group of uses. Bismuth has very low thermal conductivity among metals. It also has a high Hall coefficient. Bismuth telluride and related materials can turn a temperature difference into electricity. They can also create cooling when electric current passes through them. Other bismuth compounds absorb ultraviolet, visible, or near-infrared light. This is why bismuth is studied in sensors, solar cells, photocatalysts, and light-sensitive materials.

Types and Applications of Bismuth Metal

Commercial bismuth metal is available as ingots, bars, rods, granules, shot, needles, and powder. The chemical identity is the same, but the physical form changes how the product is used.

Ingots are a common choice for alloy plants and metal processors. They are easy to store and suitable for furnace charging. Granules, shot, and needles are easier to weigh in smaller amounts. They also melt faster because they have more surface area. Bismuth Powder is used when fine mixing or faster reaction is needed.

Purity depends on the final use. General alloy work may use standard refined bismuth. High-purity metal is needed for some semiconductor, detector, and research uses. In many metal applications, the assay is only the first check. Lead, arsenic, antimony, copper, iron, and silver may also matter.

Low-melting alloys are the largest traditional use of bismuth metal. Tin-bismuth alloys are common in low-temperature solder. Bismuth-indium-tin and other multi-metal alloys are used when an even lower melting range is needed. These alloys can join heat-sensitive parts without using the higher temperature required by many standard solders. They are used in electronics, but the exact choice depends on joint strength, wetting, thermal cycling, and brittleness.

Fusible bismuth alloys are also used in thermal safety devices. A part made from the alloy melts at a set temperature. This action can open a valve, release a spring, cut a circuit, or start another safety step. Examples include thermal fuses, safety plugs, fire sprinkler links, and heat-release devices.

Low-melting alloys also support temporary holding and forming work. A part can be fixed in place with a molten alloy and machined after the alloy becomes solid. The alloy is then melted and removed. The same idea is used for lens positioning, tube bending, and support for thin or irregular parts. Bismuth-containing alloys are also used in reusable molds and dies. Their low processing temperature shortens the heating and cooling cycle.

The expansion of bismuth during solidification helps these uses. The alloy can fill fine details and keep close contact with the part.

Bismuth is also used as a metal additive. Small additions can improve machining in some steels, aluminum alloys, copper alloys, and cast irons. Fine bismuth particles help the cutting chip break. They can also lower friction near the cutting tool. This can improve cutting speed and surface finish. Bismuth has been studied as a replacement for lead in some free-machining metals.

Bismuth also has a smaller role in nuclear and radiation systems. Liquid lead-bismuth alloys can carry heat in some reactor designs. They have a low melting point and a high boiling point. Bismuth also absorbs fewer thermal neutrons than many heavy metals. These are special engineering uses. They need strict control of corrosion, temperature, alloy composition, and radioactive products.

Types and Applications of Bismuth Compounds

Bismuth compounds combine relatively low toxicity with high density and useful optical, electrical and catalytic properties. Different bismuth materials are used in pigments, cosmetics, pharmaceuticals, low-melting alloys, catalysts, electronic materials and laboratory research. Bismuth oxides, oxyhalides, vanadates, sulfides, selenides and tellurides are also being developed for photocatalysis, thermoelectric devices, radiation shielding and advanced imaging.

Bismuth trioxide (CAS 1304-76-3) is one of the main starting materials in the bismuth chemical industry. It is a yellow oxide with the formula Bi₂O₃. It is used to make other bismuth compounds. It is also added directly to glass, ceramic, electronic ceramic, pigment, and catalyst systems.

In specialty glass, bismuth trioxide can raise density and refractive index. It can also help make lead-free glass with useful optical and sealing properties. In ceramic systems, it can lower the firing temperature or help form the required electrical phase. Uses include ceramic capacitors, ferrites, varistors, glass frits, and other functional ceramics.

Bismuth trioxide is also used in catalyst production. It may be the active oxide, part of a mixed oxide, or a source of bismuth during catalyst making.

Bismuth nitrate, bismuth hydroxide, and bismuth subcarbonate are often used as chemical raw materials:

• Bismuth nitrate (CAS 10361-44-1)can supply bismuth ions in the production of oxides, mixed oxides, catalysts, and other salts. When it is used in a water-based process, it is usually kept in an acid solution because it hydrolyzes in water. If the acid level falls, basic bismuth nitrate can form as a solid. This can change the bismuth concentration and block lines or filters.
• Bismuth hydroxide (CAS 10361-43-0) is mainly an intermediate. It can react with selected acids to form nitrate, citrate, salicylate, and other bismuth compounds. Its water content and reaction activity can affect batch calculations.
• Bismuth subcarbonate (CAS 5892-10-4) is used in selected pharmaceutical products. It is also used to make other bismuth compounds and in some ceramic or catalyst systems.

Bismuth oxychloride (CAS 7787-59-9) is the main bismuth product used in color cosmetics. It forms thin plate-like particles. These particles reflect light and give a white to silver pearl effect. They also add slip and a smooth feel to powders and creams.

Bismuth oxychloride is used in foundations, loose powders, pressed powders, blushes, eye shadow, lip products, and nail coatings. It can be used alone for a soft pearl look. It can also be mixed with mica, titanium dioxide, and iron oxides. This creates different colors, brightness levels, and coverage (The U.S. FDA lists bismuth oxychloride as a color additive for cosmetics, including products used around the eyes). The material can also be used in decorative coatings and plastics.

Bismuth vanadate (CAS 14059-33-7) serves a different pigment market. It is a bright inorganic yellow pigment. It has good color strength, heat resistance, and weather resistance. It is used in paints, coatings, and plastics. It can replace some yellow pigments that contain lead, chromium, or cadmium.

Pharmaceutical bismuth compounds are used to treat gastric dysfunction.:

• Bismuth subsalicylate (cas 14882-18-9) is used as an active ingredient in products for diarrhea and upset stomach.
• Bismuth subgallate (cas 99-26-3) is used in internal deodorant products. It helps reduce odor from flatulence and stool.
• Bismuth citrate (cas 813-93-4) is used to make citrate-based pharmaceutical products.
• Bismuth potassium citrate (cas 57644-54-9)is used in some combination treatments for Helicobacter pylori.
• Bismuth aluminate (cas 12284-76-3), bismuth subnitrate (cas 1304-85-4), and bismuth subcarbonate have also been used in gastric-protective or antacid products.

Foconsci Chemical Industry Co., Ltd.is a Chinese bismuth‑based compounds supplier. Our representative bismuth range includes Bismuth Trioxide, Bismuth Subcarbonate, Bismuth Oxychloride, Bismuth Subnitrate, Bismuth Hydroxide, Bismuth Nitrate, Bismuth Aluminate, Bismuth Subsalicylate, Bismuth Subgallate, Bismuth Nitrate Oxide, Bismuth Potassium Citrate, and Bismuth Citrate.

Bismuth in Electronic and Other High-Tech Fields

Thermoelectric materials are one of the most established high-tech uses. Bismuth telluride (cas 1304-82-1) and antimony telluride (cas 1327-50-0) alloys work near room temperature. They are used in solid-state cooling modules. These modules have no compressor and no moving refrigerant. They are used to cool sensors, laser parts, small electronic devices, laboratory instruments, and temperature-controlled boxes. The same type of material can also turn waste heat into electric power.

Thermoelectric performance depends on more than purity. Crystal direction, grain size, carrier level, density, and contact design all affect the device. Bismuth telluride powder is therefore not a complete thermoelectric product. It must be processed into a controlled material and connected to the rest of the module.

3D printing is being studied as a way to shape thermoelectric parts. Research has used bismuth telluride and antimony telluride inks to print small power-generating structures. The method could make curved or custom-shaped parts. It may also reduce material waste. But printing speed, shape accuracy, density, and electrical contact still need work.

Bismuth-based photocatalysts are another active research area. Common materials include bismuth trioxide, bismuth vanadate, bismuth tungstate, bismuth oxychloride, bismuth oxybromide, bismuth oxyiodide (cas 7787-63-5), and bismuth subcarbonate. These compounds can absorb light and create active charges on their surface. Researchers use them for pollutant breakdown, hydrogen production, water oxidation, and selected organic reactions.

Bismuth also appears in optical and electronic materials. Bismuth germanate (cas 12233-56-6) crystals are used in radiation detectors because they produce light when they absorb high-energy radiation. Bismuth ferrite (cas 12010-42-3) is studied and used in special electronic ceramics because it has both electric and magnetic behavior. Bismuth sulfide (cas 1345-07-9) is a semiconductor that responds to visible and near-infrared light. It is studied in photodetectors, solar materials, and sensors.

High-purity bismuth oxide is used in some conductive ceramics and oxide electrolytes. Bismuth-containing glass can offer high refractive index and good infrared transmission. Bismuth-doped fibers and glasses are also studied for optical amplifiers and light sources.

Bismuth-based solar materials are mainly an emerging field. Researchers are testing bismuth halides and bismuth-based perovskite-like materials as lower-toxicity alternatives to lead perovskites. The materials can absorb light and are more stable in some conditions. But their power-conversion efficiency is still lower than the best lead-based systems.

Flexible sensors are also under study. Bismuth has a high Hall coefficient. Thin bismuth films can detect changes in a magnetic field. Researchers have placed these films on flexible polymers to make sensors that can bend around a finger or wrist. Possible uses include motion tracking, wearable controls, and soft electronic devices. Long-term bending life and stable production are still key issues.

Medical research uses another property of bismuth: its high atomic number. Bismuth-based particles can give strong contrast in X-ray and CT imaging. Some particles can also absorb near-infrared light and turn it into heat. This creates interest in combined imaging and treatment systems.

Supply and Market Outlook

Most bismuth is recovered during the processing of lead, tungsten, zinc, copper, and other ores. It is often a by-product or co-product. So bismuth supply can change when the mining and refining of other metals changes.

China is the largest bismuth-producing country. The USGS Mineral Commodity Summaries 2026 estimates world mine production at about 16,000 metric tons in 2025. China produced about 14,000 metric tons. This equals about 88% of the world total.

Hunan is the main center for bismuth resources and upstream production in China. Jiangxi and other nonferrous metal regions also take part in the supply chain. Downstream chemical suppliers are found in more regions. Foconsci Chemical Industry is based in Shandong and supplies processed bismuth compounds. This is different from mining or refining bismuth metal.

China began export controls on selected bismuth items in February 2025. The controlled list does not cover every bismuth compound. Exporters and buyers must check the exact chemical, customs code, product form, end user, and final use. This work should start before the order is ready to ship.

Demand comes from several markets. Medicines and cosmetics create regular demand for controlled grades. Lead limits support bismuth in low-temperature solder, free-machining alloys, and selected pigments. Glass, ceramics, and catalysts support demand for bismuth trioxide and other inorganic compounds. Thermoelectric materials and other electronic uses have lower volume, but they need higher purity and more control.

High-tech research gives bismuth more possible uses. Photocatalysts, bismuth-based solar cells, flexible sensors, printed thermoelectric parts, and medical imaging particles are at different stages. Some already have commercial products. Some are still mainly laboratory materials.

References

• Bismuth Uses and Application Fields — Metal Encyclopedia
• Special Properties of Bismuth and Its Application Prospects in High-Tech Fields
• U.S. Geological Survey: Mineral Commodity Summaries 2026 — Bismuth
• U.S. Geological Survey: Bismuth Statistics and Information
• U.S. FDA: Regulatory Status of Bismuth Oxychloride
• U.S. DailyMed: Bismuth Subsalicylate Drug Information
• Electronic Code of Federal Regulations: Bismuth Subgallate in Internal Deodorant Products
• U.S. DailyMed: Bismuth Subcitrate Potassium Combination Product
• China Ministry of Commerce: Export Controls on Selected Bismuth Items