Why Do Magnesium Chloride Flakes Vary in Color(White & Bittern Flakes)?

Many buyers often have doubts in the magnesium chloride hexahydrate industry. They wonder why magnesium chloride flakes with the same 46% content appear as crystalclear brightwhite flakes, paleyellow or creamyellow flakes. Pure magnesium chloride crystals themselves are colorless and transparent. The color difference has nothing to do with product purity; it mainly depends on production processes and rawmaterial impurities. As a professional magnesium chloride manufacturer, reliable white magnesium chloride flakes supplier and onestop bittern flakes supplier, we will thoroughly analyze the real causes of white and yellow flakes as well as their quality differences.

I. Causes for the Color of Bittern Flakes

The paleyellow or creamyellow magnesium chloride flakes are known as bittern flakes. They are made from natural seawater bittern or saltlake brine and are traditional byproducts of the salt chemical industry. The yellow color is not an inherent property of magnesium chloride. It is formed when three types of colorcausing impurities from raw materials are enriched after hightemperature evaporation and crystallization:

1. Iron ion colloids (the main colorforming substance): Raw brine contains ferrous iron. During evaporation and heating in production, ferrous iron is oxidized by air into ferric iron, forming hydroxyiron colloids and trace ferric hydroxide particles, which create a paleyellow or tan hue. A higher iron content results in darker yellow flakes.

2. Ultrafine suspended mineral silt impurities: Coarse filtration of brine cannot completely remove tiny suspended particles. These particles become trapped inside crystals during crystallization and further reduce the transparency of bittern flakes.

In the past, most bittern manufacturers produced magnesium chloride hexahydrate bittern flakes with a content of approximately 46%, and very few products exceeded 47%. These oldstyle flakes contained relatively high levels of sulfate, sodium chloride, potassium salts and other impurities. As market requirements for product quality keep rising, bittern manufacturers now produce magnesium chloride hexahydrate bittern flakes of much better quality than before.

II. Two Major Processes for Producing White Magnesium Chloride Flakes (Essential Differences)

Many bittern manufacturers claim that they supply white magnesium chloride flakes (purified brine white flakes). Are these identical to chemically synthesized white magnesium chloride flakes? Although they look white, they differ greatly in whitening principle, impurity level and overall quality. This is the key standard adopted by white magnesium chloride flakes suppliers to distinguish highgrade and lowgrade products.

1. Deeply purified bittern white flakes (whitening achieved by impurity removal in postprocessing) Natural brine is still used as the raw material. The magnesium chloride manufacturer improves and purifies the product through postprocessing decolorization: iron removal via oxidation, floc elimination by hydrochloric acid washing, organicmatter adsorption with activated carbon, and multiple recrystallization purification to remove all colorcausing impurities and obtain white flakes. It has obvious drawbacks: only colorforming impurities can be removed. The sulfate, sodium and potassium impurities native to brine cannot be eliminated completely. Some flakes look solid white but turn slightly turbid after dissolving in water, belonging to a midrange compromise option.

2. Chemically synthesized white magnesium chloride flakes (impurities eliminated at the source for higher purity) At Yuze, a professional magnesium chloride manufacturer, we adopt the neutralization reaction of highpurity magnesium oxide and hydrochloric acid. This is our main production process. No natural brine is used, so iron ions, humus, silt and other colorcausing substances are excluded from the source. After multistage fine filtration and lowtemperature concentration and crystallization, the finished flakes are crystalclear, evenly white and free of color variation between batches. The synthesized magnesium chloride hexahydrate white flakes contain extremely low sulfate, heavy metals and alkalimetal impurities, with excellent batch stability. They dissolve into clear water without impurities and are resistant to caking. They are widely adopted in industries with relatively strict technical requirements.

III. Correction of Common Industry Misconceptions

Yuze, a magnesium chloride manufacturer with 13year experience in this sector, sorts out several misunderstandings held by customers:

1. Do products from bittern manufacturers fail to meet quality standards? Both bittern flakes and white magnesium chloride flakes can reach the 46% content standard and satisfy user and industrial specifications. Color difference does not mean substandard quality.

2. Do sulfates cause the surface discoloration? High sulfate content in bittern flakes is an accompanying impurity rather than the cause of color change.

3. Are white magnesium chloride flakes always superior? White appearance alone cannot define the quality of white magnesium chloride flakes. Other factors including content, impurities, solution clarity after dissolution and technical indicators must also be considered. We, as a white magnesium chloride flakes manufacturer, have encountered products with a very white look that form thick viscous solution after dissolution and have poor technical parameters.

4. Do highquality bittern flakes and white magnesium chloride flakes always deliver outstanding performance in practical use? The answer is no. Performance varies for different application scenarios. Highgrade products do not always work best for every application. We at Yuze once had a customer who purchased premium white magnesium chloride hexahydrate flakes for coal washing but achieved unsatisfactory results. The clear aqueous solution of synthesized white flakes cannot adhere well to coal. Ordinary magnesium chloride that forms thicker viscous solution performs better in sulfur removal and flame retardancy for coal washing.

As a longestablished magnesium chloride manufacturer, onestop white magnesium chloride flakes supplier and bittern flakes supplier, Yuze Chemical provides a full product range: highquality chemically synthesized magnesium chloride hexahydrate white flakes and economical traditional yellow bittern flakes. Relying on our own factory and 13years of expertise, we strictly control raw materials and processes for every batch. Some highend products comply with EU testing standards. Due to internal company regulations, certifications cannot be displayed publicly, yet relevant documents can be shared separately upon inquiry. Our products feature clear aqueous solution, ultralow impurities and consistent color across batches. Samples, customized packaging and bulk export orders are available. Our magnesium chloride flakes can meet most application demands in the industrial, buildingmaterial, aquaculture, feed and foreigntrade sectors.