Dolomite powder is the fine-mesh form of dolomite, ground to 200, 300, or 400 mesh for applications requiring a white mineral filler: paint (as an extender pigment that improves coverage and durability), wall putty (as the primary filler providing bulk and smooth finish), ceramic tile body (as a flux that reduces firing temperature), and rubber/plastic compounding (as an inert filler). Our Bhavnagar facility mills dolomite powder on a dedicated grinding line separate from bentonite to prevent cross-contamination.
Whiteness and mesh are the two parameters that determine dolomite powder grade and price. Whiteness is measured on a spectrophotometer against a barium sulphate standard (100% white). Our full white dolomite powder achieves whiteness above 92%, suitable for premium paint and putty applications. Off-white grades (whiteness 80–88%) are used in ceramic bodies, rubber compounding, and industrial applications where colour is less critical.
The dolomite powder grinding line at Thordi can produce 10–15 MT per day across all mesh grades. Production is scheduled based on order book — we do not stock large quantities of fine dolomite powder because extended storage can lead to moisture pickup and caking, especially during monsoon.
Technical Specifications
Factory-Direct Pricing
15–30% lower than marketplace rates. No middlemen.
Dolomite Powder in Paint and Wall Putty
In paint manufacturing, dolomite powder serves as an extender pigment — it provides bulk, improves film durability, and contributes to the paint's hiding power (opacity) at a fraction of the cost of titanium dioxide (TiO₂), the primary white pigment. A typical emulsion paint formulation contains 15–25% dolomite powder by weight. The whiteness of the dolomite directly affects how much expensive TiO₂ is needed — higher whiteness dolomite means less TiO₂ required to achieve the target shade.
In wall putty, dolomite powder is the primary filler — typically 60–70% of the formulation by weight — providing the bulk, smoothness, and white base that makes putty spreadable and paintable. Whiteness above 90% is the standard requirement for premium putty brands; off-white dolomite creates a greyish putty that requires more paint coats to cover.
Ceramic Tile Body Application
In ceramic tile manufacturing (Morbi, Gujarat — India's largest tile cluster), dolomite powder is added to the tile body formulation as a flux. During firing at 1100–1200°C, the dolomite decomposes (CaMg(CO₃)₂ → CaO + MgO + 2CO₂), and the CaO and MgO react with silica and alumina in the clay to form a glassy phase that bonds the tile body. This fluxing action reduces the firing temperature by 30–50°C compared to non-dolomite bodies — a significant energy saving for tile plants running continuous kilns.
Dolomite Powder Processing at Our Bhavnagar Facility
Our Thordi facility's dolomite grinding line operates a Raymond mill with an air classifier system calibrated for 200, 300, and 400 mesh production. Dolomite is harder than bentonite (Mohs 3.5–4 versus 2–3 for bentonite), which means mill wear rates are higher and throughput is lower per hour. We account for this in production planning — dolomite powder campaigns are scheduled separately from bentonite powder runs, with mill roll and ring replacement scheduled after every 500 MT of dolomite production.
The dedicated grinding line eliminates cross-contamination risk between dolomite and bentonite — important because even 1–2% bentonite contamination in dolomite powder can alter the whiteness and chemical composition. For paint and ceramic manufacturers who rely on consistent whiteness and chemistry, this segregation is a non-negotiable quality requirement.
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View full categoryFrequently Asked Questions
What is the difference between dolomite powder and calcite powder?
Dolomite contains both calcium and magnesium carbonates (CaMg(CO₃)₂); calcite is primarily calcium carbonate (CaCO₃). Dolomite is slightly harder (Mohs 3.5–4 vs 3 for calcite), provides magnesium in addition to calcium, and typically has slightly lower whiteness than the highest-grade calcite. For paint and putty, dolomite's hardness contributes to better scrub resistance. For agriculture, dolomite is preferred when both calcium and magnesium supplementation is needed.
Can I get a sample for whiteness testing before bulk order?
Yes. We send 500g–1kg samples of current production stock. Whiteness testing should be done on a calibrated spectrophotometer against a barium sulphate standard. We also provide our own spectrophotometer reading for the sample lot so you can cross-check against your measurement.
Do you supply dolomite powder to the Morbi ceramic cluster?
Yes. Morbi (approximately 250 km from Bhavnagar) is a regular supply destination. We dispatch truckloads (15–25 MT) to Morbi tile manufacturers with 1–2 day transit. Several Morbi-based ceramic units have been regular buyers since 2022.
Can you produce dolomite powder finer than 400 mesh?
Standard production goes up to 400 mesh (approximately 37 microns). For finer grades (500 mesh, 600 mesh), we would need to run at reduced throughput on our Raymond mill or source from a specialised ultrafine grinding mill. Let us know your target d50 (median particle size) and d95 (95% passing size) specifications and we will confirm feasibility and pricing.