What are coal water slurry additives made of?

Additives are also added to papermaking waste liquid; exactly what they are remains a secret, under the pretense of confidentiality.

Hydroxymethyl cellulose, ethyl cellulose, sodium lignosulfonate, water glass, and sodium humate in papermaking waste pulp.

Sodium lignosulfonate, celluloses, and blended surfactants in papermaking wastewater.

I don’t know, but I’d like to find out too

Depending on the specific properties of the coal, the types of additives also vary; these include dispersants, stabilizers, and various other auxiliary chemicals such as defoamers, pH regulators, enzyme inhibitors, surface modifiers, and accelerators.

Water-coal slurry additives are currently available in many different series, and the composition of these additives varies depending on the series. For example, the lignin series is produced through the copolymerization of sodium lignosulfonate and acrylic acid. Different series of additives have distinct applications; in China, for water-coal slurry gasification, additives with low cost per ton and good stability are generally preferred, while for long-distance transportation, products with higher stability may be chosen. Therefore, the selection should be based on actual circumstances.

Pulp black liquor has very poor dispersibility; it is generally used in combination with naphthalene-based water reducers to serve a role in dispersion and stabilization

Among many options, our factory uses sodium lignosulfonate

The information states that they are hydroxymethyl cellulose, ethyl cellulose, sodium lignosulfonate, water glass, sodium humate, and so on. However, the specific proportions and whether other ingredients are added are the proprietary information of the additive manufacturers, and it is likely not to be disclosed.

Water-coal slurry additives can be classified into dispersants, stabilizers, and other auxiliary agents based on their functions, among which dispersants and stabilizers are essential. Additives are one of the key technologies in the preparation of water-coal slurry; they not only directly determine the quality of the slurry but also affect its cost, with their expense being the second-largest factor in the slurry production costs.   Dispersants are a type of surfactant, mainly classified into anionic, cationic, and non-ionic types. Their international price ratio is 1:4:2. Since anionic dispersants are simpler to synthesize and cheaper, they are widely used in China, with a typical usage level of around 1%. However, their dispersing ability is inferior to that of non-ionic dispersants, and their effectiveness is often affected by soluble salts in coal and water hardness. Non-ionic dispersants (generally made from ethylene oxide) have good hydrophilicity and are not affected by water quality or soluble substances in coal during use. Although its price is higher than that of the anionic type, less amount is required, usually around 0.5%.   There are mainly five types of dispersants in use currently: 1. Humic acids or humic acid derivatives. Their advantage is that they are extracted from lower-grade coals that do not contain free humic acids, giving them good dispersing properties; however, they are sensitive to metal ions, tend to form precipitates, and result in poor slurry stability. 2. Lignosulfonates have the advantages of abundant raw material resources, low cost, easy availability, and good stability in pulping processes. However, their raw materials are complex, their properties are unstable, and their pulping performance is relatively poor, making it difficult to meet the requirements of industrial applications.  3. Naphthalene sulfonates, FDN – naphthalene-based additives (formaldehyde condensate of naphthalene sulfonic acid, with naphthalene as the hydrophobic portion and sulfonic acid groups as the hydrophilic functional groups).   The advantage is its excellent wetting properties. It has good dispersion properties, a strong ability to reduce viscosity through dispersion, an excellent flow pattern for the slurry, and a wide range of applications; however, its slurry stability is poor, it tends to release water and form irreversible hard precipitates, and its price is relatively high.   4. Polycarboxylate series: Its advantage is that the water-coal slurry prepared using it has good flowability and stability, but it is relatively expensive. It is suitable for use in preparing water-coal slurry for combustion, yet its cost-effectiveness is poor when used for preparing water-coal slurry for gasification.   5. Polyolefin series: Its advantage is its strong dispersing and stabilizing effect on low-ash coal slurries, but the molecular weight and its distribution need to be strictly controlled, and it is expensive.   The first three types are the most commonly used water coal slurry additives in China, while the two types of water coal slurry additives that are most widely used abroad are naphthalenesulfonate formaldehyde condensates and polystyrene sulfonates.   Stabilizers: inorganic salts, high-molecular-weight organic compounds such as polyacrylamide flocculants, carboxymethyl cellulose, and certain fine colloidal particles (organic montmorillonite).   Auxiliary additives: defoamers, antifungals, adjusters, surface treatment agents, accelerators, etc