Machine study of laboratory Rolls-crushers.

Theory:-

Rock crusher, also known as ore crusher, plays a vital part in crushing various types of rocks and ores. There are two types of rock crushers in actual production, that is, primary crusher and secondary crusher. Secondary crushers mainly handle rocks of smaller particle size that have already been impacted and crushed from their original size. In recent years, with the rapid development of infrastructure projects, rock crushers have found more applications in various fields and industries, such as mining, chemical industry, road construction, metallurgy, construction and so on. In this passage, several types of commonly used secondary crushers will be listed as follows.

1. Impact crusher:-

According to the nature of the materials to be crushed in actual production, impact crushers can be used for secondary crushing as well primary crushing. During operation, materials will be first fed into the crushing chamber for continuous and repeated impacting and crushing by large hammers. When the materials have been crushed to the proper particle size, they will finally be discharged from the lower part of the discharge opening. In general, impact crushers can be divided into two types, including horizontal shaft impact crusher (HSI for short), which uses hammers that swing on a rotating shaft, and vertical shaft impact crusher (VSI for short), which “throws” the material against a surface by means of the rock’s velocity to break it apart.

2. Cone Crushers :-

As a type of frequently used secondary crusher, cone crusher’s working principle is quite similar to that of the gyratory crusher. Nevertheless, the difference is that the crushing chamber in a cone crusher isn’t as steep as it is in a gyratory crusher and the positions of the different crushing zones are more parallel.

3. Roll Crusher:-

Name of roll crusher properly indicates its operating mode. The rocks and ores to be crushed will be processed between two large steel wheels, which press down on the materials and then crush the materials into smaller particle sizes to meet customers’ specific requirements.

 

Roller mills are suitable machines for fine crushing, which leads to extreme exposure of the feed in case of somewhat coarse intergrown ore avoiding further fine milling.The roll crusher equipment is a very potential force in market development of the crushing plant, roll crusher plays an important role in the process of crushing materials, the material is repeatedly crushed by the broken parts. Compared with hammer crusher and impact crusher, in the crushing of materials, the roll crusher equipment is more suitable for crushing brittle materials. Roll crusher equipment has large crushing ratio and can up to 50. This roll crusher can be used to crushing limestone in cement industry. Any company and business that use of the roll crusher equipment or are using the production of roll crusher has a deeper understanding of the improvement the utilization of crushing materials. Spare parts of roll crusher equipment is easy to replace, and has a corresponding reduction in maintenance expense. This machine is suitable for a very large hardness of materials or used for soft materials. Roll crusher equipment in daily use, the maintenance of the machine must be aware of. In particular, the operators need to pay attention to maintenance of the roller of roll crusher equipment, because the easiest to wear and consumption is the roller.

OPERATING PRINCIPLE:-

The feed material is crushed between two counter-clockwise rotating rollers to a degree of fineness allowing it to fall through a slit at the bottom. In the event that the pressure becomes too great, the rollers deflect outwardly, increasing the gap between them and consequently also the final grain size.

AREAS OF APPLICATION:-

Crushing of brittle ore in preparation of hydromechanic gravimetric sorting of medium-sized grain fractions.

REMARKS:

• Roll crushers are known for producing a ground product with a very low proportion of fines.
• 30 - 200 g of hard-steel wear per ton throughput depending on hardness and tenacity of the feed material.
• The roll crushing of hard minerals (igneous rocks, hard ores, gravel sediments) uses smooth Jaws, whereas the rollers for crushing medium hard or soft material (e.g. Iimestone, anhydrite, sedimentary Iron ores, etc. or salts, clays, soft brown coal, etc.) are fluted or serrated.
• The roller diameters should equal approx. 20 times that of that largest grain-size contained in the fee.

SUITABILITY FOR SMALL-SCALE MINING:-

Roller mills are suitable machines for fine crushing, which leads to extreme exposure of the feed in case of somewhat coarse intergrown ore avoiding further fine milling.

 

Manufacturer:- Millan, Volcan, Denver

TECHNICAL DATA:

Dimensions:

approx. 0.7 × 0.7 × 1.5 m, roller die 25 cm or more

Weight:

approx. 350 kg

Extent of Mechanization:

 fully mechanized

Power Required:

starting at approx: 5 kW

Form of           Driving Energy:

electric motor, internal combustion engine

Alternative Forms:

possibly hydromechanic

Mode of Operation:

continuous

Throughput/Capacity:   

approx. 700 kg/in

Technical Efficiency:

degree of comminution between 3:1 and 4:1

ECONOMIC DATA:

Investment Costs:

Denver mill, 2 t/h: 18.900 US $, Volcan mill, 500 kg/h: 5000 US $, Millan mill approx. 6500 DM including motor fob La Paz

Operating Costs:

labor costs, energy costs, minimal wear  

Side View of Machine:-