Refining of Raw Cane Sugar

Once raw sugar has been cleaned and melted, it enters one of the most transformative stages in the refining process: carbonation . This step is all about clarity — removing suspended impurities, reducing color, and setting the stage for high-quality crystallization. In this post, we’ll explore how carbonation works, why it’s essential, and how refineries optimize it for performance, yield, and sustainability. 🧪 What Is Carbonation? Carbonation is a chemical clarification method that uses lime (Ca(OH)₂) and carbon dioxide (CO₂) to precipitate impurities from sugar liquor. The goal is to form fine particles of calcium carbonate (CaCO₃) that trap and carry away colorants, ash, proteins, and other non-sugar materials. Think of it as a controlled snowstorm inside a tank — tiny calcium carbonate flakes form and settle, sweeping impurities down with them. This process takes place in a specialized vessel called a carbonator — a large, temperature-controlled tank equipped with agitators an...

The carbonation process is a widely used method for refining sugar from raw sugar melt. It involves the reaction of calcium hydroxide and carbon dioxide to form calcium carbonate, which precipitates and removes impurities and colorants from the sugar solution. The carbonation process has several advantages, such as low capital and operating costs, high color and turbidity removal efficiency, low sugar loss and environmental friendliness. In this blog post, we will explain the main steps and equipment involved in the carbonation process, as well as some tips and best practices to optimize its performance. The goal of the carbonation process is to eliminate impurities that make raw melt liquor cloudy. Carbonation is typically used in refineries before any decolorizing process. It has a positive effect on sugar liquors, reducing color by 40-50% and ash content by 20-25%. Lime and carbon dioxide are added to the sugar liquor to create calcium carbonate precipitates that absorb impurities a...

After carbonation has done its job — removing suspended solids and reducing color — sugar liquor still contains dissolved ions and trace colorants that can interfere with crystallization and final product quality. That’s where ion exchange resins come in. Acting like molecular magnets, these resins polish the liquor by swapping unwanted ions for more desirable ones, helping refineries achieve the clarity and consistency needed for premium sugar. Let’s explore how the process works, what types of resins are used, and why this step is critical in the refining sequence. 🧲 What Are Ion Exchange Resins? Ion exchange resins are synthetic polymer beads designed to attract and hold specific ions from solution. They work through a reversible chemical exchange — trading ions in the resin for those in the sugar liquor. There are two main types: Cation exchange resins : Remove positively charged ions like calcium (Ca²⁺), magnesium (Mg²⁺), and iron (Fe²⁺), typically exchanging them for sodium (N...