About Industrial Grade Magnesium Carbonate
Industrial grade magnesium carbonate is a white basic magnesium carbonate powder, in light or heavy form, for technical applications in rubber, coatings, inks, plastics and building materials. It combines high whiteness with low abrasiveness and a fine particle structure, so it can fill, reinforce mildly and modify flow without wearing process equipment.
In rubber, it is used as a semi-reinforcing white filler, notably in translucent and light-coloured compounds: its refractive index is close to that of natural rubber, so parts can keep their clarity at moderate loadings. In paints and printing inks it acts as an extender and flatting agent and helps control viscosity. Its thermal decomposition, which releases water and carbon dioxide, makes it useful in some fire-resistant formulations, and in construction it is used in insulating products, magnesium-based binders and dry mixes.
Obsidian Minerals produces industrial grade magnesium carbonate in Gujarat and controls assay, whiteness, moisture and coarse residue batch by batch. Light and heavy forms, and custom particle sizes, can be supplied to suit compounding, mixing or dosing equipment. Each shipment carries the MSDS/SDS, Technical Data Sheet and Certificate of Analysis, and samples are available for compound and formulation trials, with both light and heavy forms offered for side-by-side comparison.
Typical specifications
| Parameter | Typical Value | Test Method |
|---|---|---|
| Assay (as MgO) | 38.0–43.0 % | Internal method |
| Calcium as CaO | ≤ 1.5 % | Internal method |
| Iron as Fe₂O₃ | ≤ 0.05 % | Internal method |
| Moisture (105 °C) | ≤ 3.0 % | Internal method |
| Residue on 45 µm sieve | ≤ 0.5 % | Internal method |
| Whiteness | ≥ 93 % | Internal method |
| Bulk density (loose) | Light 0.10–0.25 g/cm³; heavy ≥ 0.40 g/cm³ | Internal method |
Typical values for guidance. Guaranteed limits are stated on the Technical Data Sheet and batch CoA. Particle size and bulk density can be agreed for specific applications.
Key features & benefits
Low-abrasion white filler
Industrial grade magnesium carbonate is soft and fine, so it adds whiteness and bulk to compounds and coatings with limited wear on mixers, extruders, dies and dispersion equipment.
Translucency in rubber
Its refractive index sits close to that of natural rubber, which allows translucent and pale compounds to be filled at moderate loadings while retaining a clear or light appearance.
Flatting and viscosity control
In paints and printing inks the porous particles reduce gloss and add body, helping formulators adjust sheen and rheology without moving to coarser, more abrasive extenders.
Heat-activated release of water and CO₂
On heating, the carbonate decomposes, absorbing heat and releasing water vapour and carbon dioxide, which can support fire-resistant formulations when combined with other mineral additives.
Light or heavy form
Low-density light powder maximises volume and absorbency, while heavy powder conveys and doses more easily, so the form can be matched to the plant's feeding equipment.
Applications
Translucent and light-coloured rubber
Semi-reinforcing filler in shoe soles, translucent mouldings, rubber sheeting and coloured goods where whiteness or clarity matter and carbon black cannot be used, often in combination with silica or other white fillers.
Paints, inks and coatings
Extender and flatting agent in matt and satin finishes and in printing inks, where fine, soft particles help control gloss, viscosity and pigment settling with limited wear on bead mills and dispersers.
Fire-resistant and insulation products
Ingredient in thermal insulation, fire-resistant boards and coatings, contributing heat-absorbing decomposition and low thermal conductivity in combination with other mineral components, binders and fibres used in the finished product.
Construction materials
Used in magnesium-based binders, dry-mix products and specialty mortars as a magnesium source and filler that modifies workability and setting behaviour of the mix, subject to trials with local cements and aggregates.
Usage & handling
- Rubber loadings commonly range from 20 to 80 phr depending on the hardness and translucency required; validate in your own compound.
- Pre-blend light grades with other dry ingredients or add them in stages, as low bulk density can slow incorporation in internal mixers.
- Keep bags sealed; absorbed moisture can cause porosity in rubber or lumps in dry mixes.
- Use dust extraction during charging and follow the SDS for PPE.
Packaging & supply
- 25 kg or 50 kg HDPE or paper bags
- 1 MT and 1.2 MT FIBC jumbo bags
- Custom or private-label packaging on request
Frequently asked questions
Why is magnesium carbonate used in translucent rubber?
Industrial grade magnesium carbonate has a refractive index close to that of natural rubber, so light passes through a filled compound with little scattering. That allows translucent and pale parts to carry a useful filler loading while keeping their appearance. It also provides mild reinforcement, which helps hardness and tear properties compared with an unfilled compound.
What loading of magnesium carbonate is used in rubber compounds?
Loadings commonly range from about 20 to 80 phr, depending on the polymer, the hardness target and how much translucency must be retained. Light grades add more volume per kilogram, while heavy grades are easier to incorporate. Compounders should confirm the loading through their own mixing, curing and physical property tests before adopting it in production.
Can industrial grade magnesium carbonate be used in paints?
Yes. It is used as an extender and flatting agent in matt and satin paints and in printing inks. Its fine, soft particles reduce gloss, add body and help control viscosity with low abrasion on dispersion equipment. Formulators should evaluate its effect on opacity, viscosity stability and colour in their own system.
Should I order light or heavy industrial grade magnesium carbonate?
Choose the light form when you want maximum volume, absorbency or translucency per kilogram, for example in rubber or insulating products. Choose the heavy form when handling, conveying and dosing matter more, or when dust must be limited. If both could work, we can send samples of each so you can compare them in your process.
How is industrial grade magnesium carbonate packed?
The grade is packed in 25 kg or 50 kg HDPE or paper bags, or in 1 MT and 1.2 MT jumbo bags for automated or bulk handling. Custom and private-label packaging can be arranged on request. An MSDS/SDS, Technical Data Sheet and batch Certificate of Analysis accompany every shipment.