I. Project Overview

Sulfur is an important chemical raw material widely used in rubber, pesticides, fertilizers, fireworks and firecrackers, papermaking, pharmaceuticals, and other industries. Grinding lump sulfur into powder (typically 100–400 mesh) is a key pretreatment step for downstream applications.

This solution is designed for sulfur (Mohs hardness 1.5–2.5, brittle material) using an explosion‑proof Raymond mill as the core equipment.

II. Risk Analysis and Prerequisites

2.1 Core Risks

Sulfur is a flammable and explosive material, and processing it with a Mulino Raymond presents the following safety hazards:

• Standard Raymond mills are not explosion‑proof; the heat and sparks generated during grinding may cause combustion or explosion.
• Sulfur powder tends to accumulate static electricity during comminution, which can become an ignition source.
• Sulfur dust, when mixed with air to a certain concentration, can cause dust explosions in the presence of an ignition source.
• Sulfur powder softens upon heating, which reduces mill throughput and grinding efficiency.

Critical Warning: Standard Raymond mills are strictly prohibited for grinding sulfur. A dedicated explosion‑proof Raymond mill equipped with an inert gas protection system must be used.

2.2 Prerequisites

III. Equipment Selection and Configuration

3.1 Core Equipment – Explosion‑Proof Raymond Mill

Conventional Raymond mills cannot be used directly. A sulfur‑dedicated explosion‑proof Raymond mill must be selected. Its main features are:

3.2 Complete Equipment List

IV. Process Flow

4.1 Process Flow Diagram

Lump sulfur → Jaw crusher (primary crush to ≤5 cm) → Hammer crusher (secondary crush to 1–0.5 mm) →
Bucket elevator → Nitrogen‑sealed storage bin → Enclosed vibrating feeder →
Explosion‑proof Raymond mill (nitrogen protection + cooling, grinding) → Air‑borne powder → Explosion‑proof classifier →
    ├─ Coarse powder → Returned to grinding chamber for re‑grinding
    └─ Qualified fine powder → Anti‑static cyclone collector → Finished powder discharge → Nitrogen‑purged automatic packing
         ↓
    Anti‑static pulse bag filter (purified exhaust discharged to atmosphere)

4.2 Detailed Description of Each Step

(1) Raw material selection: High‑quality sulfur crystal lumps with impurity content meeting national standards are used.

(2) Primary crushing: Lump sulfur is crushed by a jaw crusher to ≤5 cm.

(3) Secondary crushing: A hammer crusher equipped with a 2 mm screen reduces the sulfur to 1–0.5 mm.

(4) Nitrogen purging: Before the Raymond mill starts, nitrogen is introduced to displace the air inside the system, reducing the oxygen content to a safe level (≤5%–6%).

(5) Fine grinding: The pre‑crushed sulfur particles are uniformly fed into the explosion‑proof Raymond mill via the enclosed feeder and ground under nitrogen protection e cooling. The grinding fineness can be controlled within the range of 100–400 mesh as required.

(6) Classification: The ground powder is carried by the airflow to the classifier. Qualified fine powder passes through and enters the collection system; unqualified coarse powder is returned to the grinding chamber for re‑grinding.

(7) Collection and packing: The qualified fine powder is collected by the anti‑static cyclone collector and automatically packed under nitrogen protection.

(8) Exhaust treatment: The exhaust gas is purified by an anti‑static pulse bag filter before discharge.

V. Quality Control Points

VI. Safety Measures (Top Priority)

Due to the flammable and explosive nature of sulfur, safety measures are the core of the entire solution:

VII. Applications of Sulfur Powder After Grinding

Sulfur powder is an important chemical intermediate with a wide range of applications.

7.1 Main Application Areas and Recommended Fineness

7.2 Detailed Applications in Various Industries

(1) Rubber Industry (largest consumer sector)

Sulfur powder is the most critical vulcanising agent for rubber. In the production of rubber tyres, footwear, and other rubber products, sulfur powder cross‑links with rubber molecules, transforming the rubber from a plastic to an elastic state and imparting excellent physical and mechanical properties. Different fineness grades are suitable for different types of rubber products.

(2) Pesticides and Fertilizers

Sulfur powder is the main active ingredient in effective insecticides and fungicides, used for pest and disease control on fruit trees and crops. In addition, sulfur is an essential nutrient for plant growth, and sulfur powder can be used directly as a sulfur fertiliser or in the production of sulphur‑based fertilisers such as ammonium sulphate.

(3) Fireworks, Firecrackers and Gunpowder

Sulfur powder is a core component of black powder (potassium nitrate + sulfur + charcoal). Fireworks, military gunpowder, match heads, etc., all require sulfur powder.

(4) Chemicals and Dyes

Sulfur powder is used to produce basic chemical raw materials such as sulfuric acid, liquid sulfur dioxide, sodium sulfite, carbon disulfide, and thionyl chloride. In the dye industry, it is used to produce various sulfur dyes.

(5) Papermaking

Sulfur powder is used in the paper industry for pulp cooking.

(6) Building Materials and Engineering

Sulfur powder can be used to prepare sulfur cement e sulfur concrete, which feature rapid setting and high strength, suitable for rail anchoring, building repair, and other engineering applications.

(7) Food and Pharmaceuticals

Food‑grade sulfur is used for preservation, pest control, bleaching, and fumigation, as well as for softening corn and other raw materials in the starch industry. In the pharmaceutical field, it is used for the production of certain drugs and ointments.

VIII. Investment and Economic Estimates (Reference)