Iron sheet, raw material for the production of red iron oxide

The technical field of red iron oxide production, specifically relates to a method for preparing red iron oxide, using a device for preparing red iron oxide, the preparation equipment includes a reaction tank, an annular air pipe, a pumping liquid mechanism and a liquid throwing mechanism; the reaction tank is provided with an impact chamber and a stirring chamber from top to bottom, the top of the reaction tank is provided with a feeding port, and the bottom of the reaction tank is provided with a discharge port; the annular air pipe is coaxially and evenly spaced on the inner wall of the impact chamber, and the inner side of the annular air pipe is provided with a plurality of outlets extending in a direction away from its axis along its circumference; the pumping liquid mechanism is provided in the stirring chamber; the liquid throwing mechanism is provided in the impact chamber; the stirring mechanism is provided in the stirring chamber for stirring the feed liquid. The present invention also relates to a device for preparing red iron oxide. The present application can ensure that the precipitation in the feed liquid will not affect the outlet of the annular air pipe, thereby enabling the reaction efficiency of red iron oxide to be continuously and stably carried out.

Iron oxide green production workshop

The production methods of iron oxide green mainly include dry method, wet method and hydrothermal method.

1. Dry method for producing iron oxide green

Dry method for producing iron oxide green is a method of directly reacting iron and oxide under high temperature conditions to produce iron oxide green. This method has low raw material cost and low production cost, but the product quality is easily affected by raw materials and production conditions. Dry method for producing iron oxide green is suitable for fields with high demand and low requirements, such as building materials, floor paint, bricks and tiles, etc.

2. Wet method for producing iron oxide green

Wet method for producing iron oxide green is a method of reacting iron salts and alkaline compounds to produce iron oxide green. This method has a fast reaction speed and stable product quality, but the production cost is high. Wet method for producing iron oxide green is suitable for fields with high requirements for product quality, such as pigments and inks.

1. Ferrous sulfate oxidation method

Ferrous sulfate oxidation method is a common method for preparing yellow iron oxide, and its main steps include:

Preparation of ferrous sulfate: First, sulfuric acid reacts with iron filings to form ferrous sulfate (FeSO4). The reaction equation is: Fe + H2SO4 → FeSO4 + H2↑.

Crystal nucleus preparation: Add enough sodium hydroxide (NaOH) to the ferrous sulfate solution and stir continuously to convert part of the iron ions into ferrous hydroxide [Fe(OH)2]. Subsequently, air is introduced at an appropriate temperature (such as 30-35°C) to oxidize Fe(OH)2 to FeOOH to form a crystal nucleus.

Oxidation reaction: Continue to add ferrous sulfate and iron filings to the crystal nucleus suspension, heat and blow air to carry out oxidation reaction. In this process, Fe2+ is oxidized to Fe3+ to form yellow iron oxide (the main component is Fe2O3·H2O). The reaction equation can be simplified to: 4Fe(OH)2 + O2 → 4FeOOH + 2H2O.

Post-processing: After steps such as filtration, rinsing, drying, and crushing, the iron oxide yellow product is finally obtained.

The production process of red iron oxide is a complex and delicate process, which mainly includes raw material preparation, acid leaching, hydrolysis, oxidation, calcination, grinding and grading. The following is a detailed introduction to these steps:

1. Raw material preparation

The raw materials for the production of red iron oxide mainly include iron ore, sulfuric acid, nitric acid, etc. First, the raw materials need to be screened and pretreated to ensure the quality and purity of the raw materials. For iron ore, it needs to be crushed, ground and other treatments so that the subsequent chemical reaction can be fully carried out.

2. Acid leaching

The pretreated iron ore is mixed with sulfuric acid or nitric acid for acid leaching. In this process, the iron element in the iron ore will react chemically with the acid to produce ferrous sulfate or ferrous nitrate solution. By controlling the temperature, time and acid concentration of the reaction, the sufficient leaching of the iron element can be ensured.

3. Hydrolysis

The ferrous sulfate or ferrous nitrate solution obtained by acid leaching is hydrolyzed to produce ferrous hydroxide. In this process, an appropriate amount of alkali solution (such as sodium hydroxide) needs to be added to combine the ferrous ions in the solution with the hydroxide ions to form ferrous hydroxide precipitation.

IV. Oxidation

The obtained ferrous hydroxide precipitate is oxidized to convert it into iron oxide. This is usually achieved by calcining in air. During the calcination process, ferrous hydroxide is decomposed by heat to generate iron oxide and water vapor. By controlling the temperature and time of calcination, the quality and color of the iron oxide can be ensured.

V. Calcination

The material after oxidation treatment needs to be further calcined to obtain iron oxide red. The calcination temperature is usually between 700-800℃, and the specific temperature depends on the color and quality of the required product. During the calcination process, the materials need to be fully mixed and evenly heated to ensure the uniformity and stability of the product.

VI. Grinding and grading

The iron oxide particles obtained after calcination are large and need to be ground to obtain the required particle size. The ground material also needs to be graded to divide it into products of different particle sizes to meet the needs of different customers. The grading process is usually carried out by screening or airflow classification.

VII. Packaging and storage

The ground and graded iron oxide is packaged for transportation and storage. During the packaging process, the product's sealing and moisture resistance must be ensured to prevent the product from being damp or otherwise contaminated during storage and transportation.