Lithopone production: a practical process overview
An overview of co-precipitation, filtration, thermal processing, milling and the quality checks relevant to a finished lithopone grade.
Bài viết này hiện có bằng tiếng Anh.
From dissolved feedstocks to composite pigment
Lithopone, sometimes referred to as Lide powder, is a zinc sulfide and barium sulfate composite white pigment. The general production route begins with a double-decomposition reaction between barium sulfide solution and zinc sulfate solution, forming a co-precipitate.
The reference process is commonly summarized as precipitation, filtration, thermal treatment, grinding, drying and classification. The exact equipment and operating conditions vary by producer and grade. This article gives a technical overview rather than an operating procedure or a description of a specific Longtai production line.
Precipitation, separation and washing
Precipitation establishes the composite material. Separation and washing remove the process liquid and help control residual soluble matter. These stages influence the consistency of the material entering subsequent treatment.
Buyers normally assess the resulting product through its agreed specification and inspection information rather than attempting to infer quality from a simplified process diagram.
Thermal treatment, milling and finishing
Controlled thermal processing influences pigment characteristics. Subsequent wet or dry grinding, drying and classification help produce the particle distribution and powder condition needed for handling and dispersion.
Process quality matters because coarse material, excess moisture or inconsistent dispersion can affect the finished paint, rubber or plastic product. A bright appearance alone does not demonstrate that these characteristics are controlled.
What quality information should a buyer request?
| Area | Relevant information |
|---|---|
| Grade identity | The exact product and agreed specification. |
| Composition and optical behaviour | Specified composition and results under stated test methods. |
| Powder condition | Moisture, residue and handling-related characteristics. |
| Application performance | A representative trial in the intended binder or polymer. |
| Traceability | Batch identification and available inspection records. |
Keep the sample reference, test conditions and purchase specification together. If a delivery behaves differently, this information helps the supplier investigate the difference.
Connecting the process to your application
Review B-301 and B-311 using current product data. For coatings, assess dispersion and dry-film properties; for rubber and plastics, include processing and the mechanical or appearance requirements of the finished article.
The NIST Chemistry WebBook: barium sulfide identifies one feedstock mentioned in the general reaction. It is a different substance from the finished lithopone pigment; use the SDS for each material actually handled.
Frequently asked questions
Is lithopone made by simply blending two powders?
The pigment family is generally based on co-precipitated zinc sulfide and barium sulfate, followed by further processing.
Does a production summary guarantee a grade’s performance?
No. Use the agreed specification, batch records and application testing.
Where can I ask about a Longtai grade?
Discuss your application with Longtai Chemical. Include the target grade, required quantity, packaging and destination port so the team can prepare a relevant product recommendation and quotation.
