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...

 Before sugar becomes the sparkling white crystals we stir into our coffee, it goes through a fascinating transformation. The first major steps in this journey are affination and melting — two processes that clean and dissolve raw sugar to prepare it for refining. In this post, we’ll explore how these steps work, why they matter, and how modern refineries optimize them for quality and efficiency. 🧪 What Is Affination? Affination is like giving raw sugar a deep cleanse. Raw sugar crystals are coated in molasses and other surface impurities that can interfere with refining. Affination washes these away, making the sugar easier to process and improving the final product’s clarity and purity. Why It’s Done: Removes molasses and color bodies Reduces ash, starch, and dextran Improves filterability and reduces turbidity How It Works: Mixing : Raw sugar is blended with a warm, saturated syrup (called affination syrup) to loosen surface impurities. Centrifugation : The mixture is spun in a...

Rotary pressure filters are extensively utilized in the sugar industry to filter carbonated liquor , a solution consisting of sugar and lime that has undergone carbonation to eliminate impurities. These filters are known for their ability to conduct both pressure filtration and cake washing within a single unit. A rotary pressure filter comprises a cylindrical drum that rotates at a gradual pace either horizontally or vertically. The drum is partitioned into multiple sections, each equipped with its individual filter medium, commonly made of cloth, and designated process zone. The drum is enclosed within a pressure vessel, which contains the feed slurry, wash liquid, and filtrate. Rotary pressure filter involves several key steps for proper filtration- Distribution: Carbonated liquor, containing a mixture of sugar crystals and molasses, is evenly distributed onto a filter medium (typically a cloth) that covers a rotating drum. The drum is divided into compartments, each filled with t...

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...