Dolomite, also known as dolostone, is a carbonate mineral and one of the common rocks in the Earth's crust. Its crystal structure is similar to that of calcite, usually occurring in rhombohedral form, with crystal faces often curved into a saddle shape.

Physicochemical Properties of Dolomite

Hardness: It has a Mohs hardness of 3.5–4.0, belonging to medium hardness, which makes it easy to process and carve.

Density: With a density of 2.8–2.9 g/cm³, its relative density is moderate, facilitating transportation and application.

Crystal Structure: It exhibits a rhombohedral form, with crystals often curved into a saddle shape; aggregates are mostly granular or massive.

Luster: It has a vitreous luster, featuring a smooth surface and good light reflection.

Color: It is mainly grayish-white, but may appear grayish-green, grayish-yellow, pink, or other colors due to impurities.

Classification of Dolomite

As a widely occurring mineral in nature, dolomite is mainly classified based on factors such as origin and chemical composition. According to its formation stage and composition, dolomite can be divided into several types:

Syngenetic Dolostone: Formed in the early stage of sedimentary diagenesis, it has a uniform and dense texture with fine particle size.

Diagenetic Dolostone: Formed when calcium carbonate is replaced by magnesium ions during the diagenetic process, it features a fine-grained structure and replacement traces.

Epigenetic Dolostone: Formed when already consolidated limestone is further replaced by magnesium ions, it has an uneven replacement structure and coarse dolomite particle size.

Deep Processing and Grinding of Dolomite

The transformation of dolomite from a basic mineral to a high-value-added product cannot be achieved without the support of efficient and intelligent grinding equipment. With MTW European trapezium grinding mill and LM vertical roller mill as the core, Shanghai Zenith has built a grinding ecosystem featuring "low energy consumption, high precision, and zero pollution".

Process Flow of MTW European Trapezium Grinding Mill

Raw materials are uniformly, quantitatively, and continuously fed into the grinding chamber of the main machine via a variable-frequency belt feeder for grinding. After grinding, the materials are carried by the fan airflow to the classifier for classification. Under the action of the analyzer, materials that do not meet the fineness requirements fall back into the grinding chamber for re-grinding, while qualified materials are transported with the airflow through pipelines into the cyclone powder collector for separation and collection. The finished powder is discharged through the discharge device.

The separated airflow enters the fan through the return air pipe at the upper end of the cyclone powder collector. This production system operates under negative pressure and airtight conditions, and is equipped with a pulse dust collector to prevent dust leakage, complying with national environmental protection standards.

Process Flow of LM Vertical Roller Mill

The motor drives the reducer to rotate the grinding disc. Materials are fed into the center of the grinding disc through air-locking feeding equipment, and move to the edge of the grinding disc under the action of centrifugal force, then enter the grinding roller track. Under the pressure of the grinding rollers, the materials are crushed by extrusion, grinding, and shearing.

At the same time, hot air is blown out at high speed from the air ring: it blows up the ground materials, with coarse-grained materials blown back for re-grinding; suspended materials are dried, and fine powders are carried by the hot air into the separator for classification. Qualified fine powders are discharged with the airflow and collected by dust collection equipment, while coarse powders fall back to the grinding disc under the action of the separator and are re-ground together with new materials, completing the grinding operation through circulation.

With a complete R&D system, large-scale production bases, advanced product production lines, and a high-quality market service system, Shanghai Zenith has provided customized dolomite processing solutions for numerous enterprises.

Choosing Shanghai Zenith means not only selecting a piece of equipment, but also partnering with a reliable industrial collaborator.