Iron ore washing process

Mineral processing technology and technology of iron ore

Iron ore in China is mostly poor ore (accounting for 97.5% of the total reserves) and other ores with complex composition (1/3 of the total reserves), so most of them need to be beneficiated before smelting.

196 214.97 million tons of iron ore were selected nationwide, accounting for 85.2% of the 252.28 million tons of raw iron ore produced nationwide. The selected iron ore produced 85.857 million tons of iron concentrate, of which the key concentrator treated 65.438+0.096 1.0000 tons of raw ore and produced 4.65438+0.58 million tons of iron concentrate, accounting for 48.4% of the national iron concentrate output.

ore reduction

China's concentrator generally uses the three-stage crushing process of coarse crushing, medium crushing and fine crushing to crush iron ore. Coarse crushing adopts 1.2m or 1.5m rotary crusher, medium crushing adopts 2. 1m or 2.2m standard cone crusher, and fine crushing adopts 2. 1m or 2.2m short-headed cone crusher. After coarse crushing, the ore fragmentation is not more than 1m, and then after medium crushing and fine crushing, the final product with particle size less than 12mm is screened and sent to the grinding tank.

(2) Grinding process

In China, most iron ore grinding processes adopt two-stage grinding process, and most small and medium-sized concentrator adopt one-stage grinding process. In recent years, due to the emergence of new fine screen regrinding technology, some concentrator has changed from two-stage grinding to three-stage grinding. Generally, there are few grinding equipment, the largest ball mill is 3.6m×6m, the largest rod mill is 3.2m×4.5m, the largest autogenous mill is 5.5m× 1.8m, and the largest gravel mill is 2.7m×3.6m.

Spiral classifier is basically used for classification after grinding. In order to improve efficiency, some concentrator use hydrocyclone instead of two-stage spiral classifier.

(3) Sorting technology

1. Magnetite dressing

Because ore is magnetic and easy to grind, domestic magnetic separation plants all adopt stage grinding and multi-stage grinding processes. For coarse-grained magnetite, the former (one-stage grinding) is adopted, and for fine-grained magnetite, the latter (two-stage or three-stage grinding) is adopted. A series of permanent magnets developed in China make the magnetic separator permanent. After the 1970s, the new technology of fine screen regrinding was popularized in the national magnetite concentrator, which increased the concentrate grade from 62% to about 66%, meeting the requirement of the Ministry of Metallurgical Industry that the concentrate grade should reach 65%.

2. Mineral processing of weakly magnetic iron ore

It is mainly used to separate hematite, limonite, specularite, siderite, pseudohematite or mixed ore, which is called "red ore". This kind of ore has low grade, fine disseminated particle size, complex mineral composition and difficult separation. Since 1980s, the research on technological processes, equipment and new reagents such as roasting magnetic separation, wet high-intensity magnetic separation, weak magnetic flotation and gravity separation has been continuously improved, and the concentrate grade and metal recovery rate have been improved.

3. Mineral processing of polymetallic * * * (associated) ore

The composition of this kind of ore is complex, there are many kinds, and the methods, equipment and flowsheet adopted are also different. For example, Baiyun Obo Iron Mine adopts reverse flotation-multi-gradient magnetic separation, flocculation flotation, weak magnetic-reverse flotation-high intensity magnetic separation, weak magnetic-positive flotation, roasting magnetic separation and other different processes. In order to improve the recovery rate of iron and comprehensively recover rare earth oxides. Panzhihua iron mine obtained ferrovanadium concentrate by magnetic separation, and the iron grade was about 53%. The tailings after magnetic separation are subjected to weak magnetic scavenging-high intensity magnetic separation-gravity separation-flotation-dry electrostatic separation to obtain titanium concentrate and sulfur cobalt concentrate, and titanium and cobalt are recovered. Iron, copper, cobalt, sulfur and other elements are comprehensively recovered by weak magnetic-strong magnetic and flotation in Daye Iron Mine.

Xinhe machinery has been committed to the research of new mineral processing technology for more than 30 years. The technical research and development department of new environmental protection iron ore beneficiation equipment of Xinhe Machinery is a professional organization specializing in the research and development of iron ore beneficiation technology. It develops and produces a series of iron ore beneficiation equipment, continuously improves the technology according to customer feedback and physical characteristics of iron ore, and has a large number of iron ore customers' beneficiation examples and rich iron ore beneficiation experience. If you want to know more about hematite beneficiation technology, please call the iron ore beneficiation equipment expert of Xinhe Machinery for free consultation: 40065963 17, and we will provide you with more iron ore beneficiation technical support for free! Baidu Maps