What are the differences between the properties and separation processes of barite and witherite?

Barite is a non-metallic mineral product with barium sulfate as the main component (chemical composition: BaO: 65.7%, SO3: 34.3%. There are isomorphous substitutions of Sr, Pb and Ca in the composition), quartz-barite veins, fluorite-barite veins, etc., and often coexists with galena, sphalerite, chalcopyrite, cinnabar, etc. Pure barite is white and shiny. And is often gray, light red, light yellow, etc. due to the influence of impurities and mixed materials.

Barite is mainly used in the petroleum, chemical, coating, filler, construction and other industrial sectors, among which oil drilling mud weighting agent is its most important use. At the same time, barite has the ability to absorb X-rays, and is used to make barium cement, barite mortar and barite concrete to replace metal lead plates to shield nuclear reactors and build scientific research and hospital buildings to protect against X-rays.

Witherite is another major barium-containing mineral in nature. It has a high specific gravity and low hardness (chemical composition: BaCO3, containing 77.7% BaO and 22.3% CO2, often containing trace amounts of Sr, Ca, Mg, and replacing Ba). Common colors are colorless, gray, and white, with a glassy luster and an oily luster on the fracture. Common forms: orthorhombic system, rare crystals, and aggregates are mostly dense blocks or fibers, grapes, etc.

Witherite is mainly used to produce zinc barium white and barium compounds, which are widely used in rubber adhesives, pesticides, oil additives, paper brighteners, drilling mud weighting agents, and getters and adhesives for televisions and other vacuum tubes.

The ore characteristics of barite and witherite are basically the same. According to their mineral processing performance, they can be divided into three categories:

(1) Easy-to-select ore: The composition and the separation process is simple. Generally, hand separation, photoelectric separation, desliming or simple gravity separation and flotation are adopted.

(2) Selectable ore: There are many available components and the mineral processing technology is relatively complicated. It is usually divided into several gravity separation, photoelectric separation, flotation or gravity and flotation combined separation, and sometimes magnetic separation is also used.

(3) Difficult-to-select ores: The main mineral properties are slightly different, the mineral particles are small, and the mineral processing technology is in the research and exploration stage.

The ore characteristics of barite and witherite are basically the same, and they can be divided into the following types according to their mineral composition:

(1) Monomineral barite ore: The mineral composition is mainly barite (BaSO4 content reaches 80~98%), with very few associated minerals.

(2) Quartz-barite ore: It is mainly composed of quartz and barite. The quartz content is generally 30~50%. The particle size of quartz has an important influence on the quality of the ore.

(3) Fluorite-barite ore: Barite and fluorite are the main minerals, and other associated minerals may include quartz and calcite，and etc.

(4) Sulfide ore - barite ore: mainly composed of barite and sulfide minerals such as iron sulfide, copper sulfide, lead sulfide, zinc sulfide, etc., accompanied by quartz, fluorite, calcite, etc.

(5) Iron ore-barite ore: It is mainly composed of barite and iron ore (such as magnetite, hematite, goethite), accompanied by quartz, calcite and other minerals.

(6) Clayey or sandy barite ore: This type of ore contains different amounts of clay, rock fragments, single mineral barite fragments, etc.

Witherite Types:

(1) Single witherite type: The ore minerals are mainly witherite, and contain almost no or only a small amount of other minerals.

(2) Witherite-barium calcite type: The ore is composed of witherite and barium calcite in different proportions, and may be accompanied by impurities such as barite, alkali stone, quartz, and carbon.

(3) Witherite-Baryte Type: The ore contains both witherite and barite, which may coexist in different proportions and may also be accompanied by other minerals such as quartz, pyrite, etc.

(4) Mixed type: The ore is composed of two or more groups of barium minerals, such as a combination of witherite, baryte and barite, or contains other minerals such as barium ferrite, accompanied by impurities such as quartz, carbonite, pyrite, etc.

The beneficiation processes of witherite and barite vary due to the different ore properties, associated minerals and industrial needs. The following is a detailed description of the beneficiation processes of the two:

Barite beneficiation process

         The barite beneficiation process varies depending on the properties of the ore. Common beneficiation methods include hand selection, gravity separation, flotation, magnetic separation, calcination, leaching and multi-process combined methods.

Manual separation: suitable for relatively pure barite ores. Manual separation is carried out by using the differences in color and density.

Photoelectric sorting method: suitable for barite ores with specific colors or surface characteristics. Choose ore color sorting equipment or artificial intelligence sorting machine for sorting.

Gravity separation method: Use the difference between the density of barite and gangue minerals to separate. It is suitable for barite ores with simple composition and coarse particle size. The process includes crushing, screening, jigging, shaking table and other steps.

Flotation method: Separation is carried out by utilizing the characteristics of barite's high specific gravity and good floatability. It is suitable for barite ores associated with sulfide ores or barite ores with fine mineral distribution, low ore grade and high concentrate grade requirements. The process includes grinding, classification, flotation and other steps.

Magnetic separation: It uses magnetic difference to separate, and is mainly used to remove iron-containing minerals from barite-associated minerals. It is often used in combination with gravity separation.

Calcination method: used to purify and whiten barite, remove moisture from the ore and impurities that can be oxidized and decomposed at high temperatures. The process includes calcination, impurity removal, cooling and other steps.

Leaching method: used to remove colored impurities such as carbon, iron, manganese, vanadium and nickel in barite. It includes acid leaching, oxidation-reduction method and organic acid complex method.

Multi-process combination method: For complex ores, multiple beneficiation methods are used for combined processing, such as gravity separation-flotation combined process.

 Witherite Beneficiation Technology

 Photoelectric sorting method: suitable for some low-grade or well-dissociated ores, mainly through intelligent sorting equipment to pre-sort and discard low-grade or associated ores.

Chemical purification method: suitable for high-grade rich ores. Process flow: grind the witherite ore powder to a certain particle size (such as less than 20 mesh), add it to the prepared ammonium chloride solution, heat and stir to decompose and remove impurities to obtain barium chloride solution. Then add ammonium carbonate to obtain barium carbonate product, or directly concentrate the barium chloride solution, cool and crystallize to obtain BaCl2·2H2O product.

High temperature decomposition method: using the characteristics of witherite decomposition under high temperature conditions, the water-insoluble carbonate is converted into water-soluble oxides, thereby converting solid minerals into liquid components. Process flow: direct calcination or calcination with carbon powder (coke powder), and then adding the clinker to the ammonium chloride solution to obtain crude barium chloride, and then remove impurities, concentrate and crystallize to obtain the product.

High temperature decomposition-chemical purification mixed method: combining the advantages of high temperature decomposition and chemical purification for mixed treatment.

In summary, the beneficiation processes of witherite and barite vary due to their ore characteristics and industrial needs. In practical applications, appropriate beneficiation processes should be selected according to specific circumstances to achieve the best economic benefits and product quality.

Mingde Optoelectronics mainly uses photoelectric sorting equipment to sort barite and witherite. At present, the equipment used includes ore color sorter to sort barite and artificial intelligence sorter to sort witherite. The equipment mainly recognizes and sorts the ore based on the color difference or surface color, texture, shape, luster,quality and other characteristics.