Calcium carbonate (Calcium Carbonate), with the chemical formula of CaCO3, is a white solid powder, tasteless, odorless, neutral, basically insoluble in water, soluble in hydrochloric acid. The calcium content is 40%, and it is the most widely used calcium source in the market.
From the production process, there are three main categories: heavy calcium carbonate, light calcium carbonate and biological calcium carbonate. In the food, dairy products, health care products and other industries, calcium carbonate can be used as an additive. Its absorption rate as a calcium supplement can reach 39%, second only to calcium tartaric acid. Because it is soluble in gastric acid, it has become a calcium supplement with more dosage forms and more applications.
Food grade calcium carbonate granules are made of food grade calcium carbonate with starch or dextrin as a binder. They have good compressibility and can be directly pressed into tablets as a raw material for calcium supplements.
Product name: Light Calcium carbonate | ||||
Main ingredient: Light Calcium carbonate | ||||
Items | Standard values | (Ref.Standard) | ||
Sensory index | Appearance | White or gray- white powder | USP | |
Physical and chemical index | Assay, ω/% | 98.0~100.5 | USP | |
Loss on drying, ω/% | ≤2.0 | USP | ||
Insolubles in hydrochloric acid, ω/% | ≤0.2 | USP | ||
Dissociate alkali | Pass | USP | ||
Magnesium and Alkali metal, ω/% | ≤1.0 | USP | ||
Barium/(mg/kg) | ≤300 | USP | ||
Arsenic/(mg/kg) | ≤3.0 | USP | ||
Fluorine/(mg/kg) | ≤50 | USP | ||
Lead/(mg/kg) | ≤3.0 | USP | ||
Mercury/(mg/kg) | ≤1.0 | USP | ||
Cadmium/(mg/kg) | ≤2.0 | USP | ||
Preservation methods | Ventilation,clean, room temperature,dry,not be mixed with poisonous and corrosive substances | |||
Shelf Life | The shelf life is 24 months from the date of production and the original packaging is in good condition | |||
Packing | 25k/ bag |
There are two primary granulation methods that can be used to produce calcium carbonate granules: wet granulation and dry granulation. Since starch and dextrin are used as binders that are typically dissolved in water, wet granulation is the preferred method for this process.
2.1. Wet Granulation Process
The wet granulation process involves agglomerating calcium carbonate powder by adding a liquid binder solution (containing starch or dextrin) to form granules. Here’s a step-by-step guide:
3. Step-by-Step Wet Granulation Process
3.1. Mixing
• The first step is to thoroughly mix the calcium carbonate powder with the dry binder (starch or dextrin) to ensure uniform distribution. This is often done using a high-shear mixer or a low-shear blender, depending on the batch size and equipment available.
3.2. Addition of Binder Solution
• After the dry materials are mixed, a binder solution (starch or dextrin dissolved in water) is slowly added to the mixture. The amount of binder solution added depends on the desired granule size and strength. The solution is added slowly while the mixture is stirred continuously to prevent clumping or over-wetting.
• The objective is to achieve a damp mass of calcium carbonate particles that are just wet enough to stick together but not too wet to form lumps or slurry.
3.3. Granulation
• During the granulation step, the damp mass is subjected to mechanical forces that help form granules. There are several types of equipment that can be used for this step:
• High-Shear Granulator: This machine uses an impeller to mix and agglomerate the powder, forming granules as the binder solution is added.
• Fluid Bed Granulator: In this method, calcium carbonate powder is fluidized by a stream of air, and the binder solution is sprayed into the fluidized powder. This method produces highly uniform granules.
• Pan Granulator or Drum Granulator: The powder and binder solution are tumbled in a rotating pan or drum, causing the particles to agglomerate and form granules.
3.4. Drying
• After the granules are formed, they are wet and need to be dried to remove the moisture from the binder solution. Drying can be performed using:
• Fluidized Bed Dryer: The granules are fluidized by hot air, allowing for efficient drying without damaging the granule structure.
• Tray Dryer: The wet granules are spread evenly on trays and dried in a heated chamber.
The drying step is crucial to harden the granules and ensure that they remain intact during handling and transport.
3.5. Screening and Sizing
• Once dried, the granules are passed through a sieve or screen to ensure uniform particle size. Oversized granules can be crushed and reprocessed, while undersized particles can be returned to the granulation process.
• The granule size typically ranges from 0.2 mm to 2 mm, depending on the application requirements.