Briefly describe what the purpose of roasting is, and what the purpose of roasting is

(1) The non-oxide minerals in the ore are turned into oxides, which will be transferred into the solution to extract metals in the hydrometallurgical process, and will be reduced to a metal state in the pyrometallurgical process.

2) Remove water and other volatile components (such as arsenic, antimony, etc.) that are harmful to the metallurgical process in the ore.

According to the purpose of the process, roasting can be roughly divided into: oxidation roasting, salt roasting, reduction roasting, volatile roasting, sintering roasting, of which salt roasting includes sulfuric roasting, chlorinated roasting and soda.

Roasting, magnetized roasting belongs to reductive roasting. According to the movement state of the material in the smelting process, it is divided into fixed bed roasting, moving bed roasting, fluidized roasting and floating roasting.

The crushed solid raw materials are roasted in oxygen to convert the useful components into oxides, and at the same time remove volatile impurities such as arsenic, antimony, selenium, and tellurium. In the sulfuric acid industry, pyrite is roasted to produce sulfur dioxide.

It is a typical oxidative roast. Oxidative roasting is widely used in the metallurgical industry, such as copper sulfide.

Ore and zinc sulfide ore are oxidized and roasted to obtain copper oxide.

Zinc oxide, and at the same time sulfur dioxide is obtained.

Roasting is the process of heating the material below the suitable atmosphere and melting point to make the target components in the raw material undergo physical and chemical changes, and its purpose is to change the chemical composition and physical properties of the material for further processing. Transform some insoluble minerals in raw materials into easily dissolved compounds; Minerals that have been removed from organic matter or certain impurity-containing components are transformed into forms that are difficult to leach; Improve the structure and structure of the impregnated material

The purpose of roasting is to turn the non-oxide minerals of the vertical slag in the ore into oxides, which are transferred into solution to extract metals in the hydrometallurgical process and reduced to a metallic state in the pyrometallurgical process. or remove water and other volatile components (such as arsenic, antimony, etc.) that are harmful to the metallurgical process in the ore.

Roasting is the process of forming a chemical reaction at a temperature lower than the melting temperature of the material, which is an integral part of the preparation of the charge. The vast majority of the material always exists in a solid state, so the roasting temperature is limited to ensure that the material does not melt significantly. Obviously, the roasting reaction is mainly a solid-gas reaction, and sometimes there are solid-solid, solid-liquid and gas-liquid interactions or interactions.

The roasting workshop is an important part of the production of ceramic products. In the roasting workshop, through a series of processes such as heating and cooling, the ceramic material obtains the required physical and chemical properties to form the manufacturing process of the finished product. Its main process characteristics are as follows:

1.High-temperature work: The roasting workshop needs to be carried out in a high-temperature (more than 1000) environment, and professional equipment such as high-temperature furnaces are required, so special furnace structure and technology are required to ensure that the furnace body is not worn.

2.High stability requirements: In the roasting process, heat transfer occurs inside the ceramic body, and the requirements for the uniformity, uniformity and stability of the ceramic products are relatively high.

3.Air circulation: During the process, it is necessary to ensure air circulation and continuously provide fresh air to ensure the effect of roasting and avoid the occurrence of high carbon dioxide content and low oxygen content.

4.Temperature change: In the process, it is necessary to carry out multiple firing and cooling processes, and the temperature change has a great impact on the quality and performance of the finished product, and the temperature change needs to be controlled by controlling the heat transfer and flow.

In short, the process characteristics of the roasting workshop are carried out under environmental conditions such as high temperature, oxygen circulation, temperature change, etc., and the quality of the product needs to be ensured through the corresponding equipment and process chain, and at the same time, it is necessary to strictly abide by the safety rules and regulations to ensure the production safety of the workshop.

Particles of white copper Cu2S were found in the slag collected in the roaster, and it is speculated that the roasting process is as follows: first, dig the first furnace pit with a diameter of about 2 meters in the relatively flat part of the hillside, first lay a layer of charcoal in the pit, pile the ore on it, and then use grass and mud to seal the ore (the purpose is to reduce heat loss). There are a number of circular smoke exhaust (SO2) holes and air vents on the sealing mud.

When the charcoal is ignited and blasted inside, the roasting reaction begins. As the roasting reaction is an exothermic reaction.

Therefore, when the ore is heated to the first temperature, there is no need to replenish the fuel, and the roasting reaction can continue.