In the present economic climate, expense base is a significant consider handling an effective quarrying business, as well as put on prices related to cone crushers can be a major price centre. This paper explains a technique to reduce wear costs by hardfacing crusher linings. Although this process is not new to the quarrying sector, it is not the norm, as there are several sceptics who have actually tried it in the past with bitter memories. Nevertheless, the procedure has been refined in recent years as well as can work well in the right applications.
Cone crushers run by having stone fed right into the top of the crusher chamber. The chamber is lined with wear parts, specifically the mantle and also dish linings. As the stone drops though the choked chamber, crushing is attained when the activity of the mantle triggers compressive as well as rough forces to act on the stone and dish lining, creating the stone to break.
Linings are produced from manganese steel as opposed to typical steel as the manganese material provides protection against abrasion (regular steel typically has a lower tolerance to put on than crushing tasks require). Relying on the rock being squashed, the percent of manganese in the linings can differ from around 12% to 23%. Care needs to be taken throughout option, as inadequate manganese will not shield the lining, while excessive can lead to brittleness in the lining, causing failing not through wear yet through cracking. In any case, the price of manganese can be significant however, as this paper will certainly show, this can be reduced.
With continued usage the crystal framework of manganese steel adjustments, becoming much more dense. This takes place when the rock being squashed is compelled against the liner causing it to 'work-harden'. 'Green' manganese begins at around 25 Rockwell (250 Brinell) and also can attain a firmness of approximately 60 Rockwell (660 Brinell) after a duration of work-hardening.
Cone Crusher Liner Selection
When selecting a crusher the bowl liner also varies in type:
- Coarse: wide inlet aperture
- Medium: medium inlet aperture
- Fine: small inlet aperture
Once again, selection depends upon the product required and the feedstock. Consultation with manufacturers is essential, some of whom will provide computer design facilities and offer wear-analysis services on both their own and other makes of crusher, such is the level of competition.
Health and safety implications
On a lot of cone crushers, rough-cast manganese liners are fitted to the head assembly as well as concave utilizing an epoxy material typically called crusher backing. Exposure to this support product has actually been recognized to cause situations of sensitization, a problem which can cause individuals having violent allergies upon minute exposure, triggering feasible breathing failing. Any type of reduction in wear component modifications will certainly not only lower exposure to backing substances (an enhancement to employees function conditions required under COSHH), but also lower the use of cranes or overhead winches, thus further minimizing the frequency of potentially dangerous circumstances. Some cone crushers do not make use of support but rather have precision-cast and machined liners. Job to minimize endure these has actually been carried out but is not talked about in this paper.
Among the most usual sources of wear is the silica web content of the rock being squashed.
Rock with a low silica material, eg good-quality sedimentary rock, does not generally give rise to high wear expenses, whereas rock which consists of a high silica part, eg sandstone, sand and gravel etc, usually does. The problem is usually run into as quickly as the linings are fitted, with the manganese being deteriorated before it has a chance to work-harden. The resulting wear prices can be substantial, as brand-new liners, cranes, fitters and connected downtime are generally all included.
Hardfacing
In order to avoid liner wear during the initial period of work-hardening, expert contractors can layer the linings with a protective surface. This process needs to be accomplished with terrific care since the manganese liners can distort and/or shrink throughout the procedure, creating a bad suit the crusher. Tiny distortions are usually not a trouble in crushers utilizing backing compound, as the support product compensates for any such irregularities. To use the protective finish, the lining is placed on a rotating turntable as well as carefully preheated. A grain of 3mm thick chrome carbide is bonded on the liner as the table rotates. The areas needing therapy are established by the wear pattern on a regular collection of linings, and by explore resultant wear patterns on treated liners. Hardfacing can offer the linings a safety finishing of approximately 62 Rockwell until it is diminished, yet by now the manganese should have work-hardened to its maximum solidity of around 60 Rockwell.
In tests embarked on at Quarry the mantle of a basic 3ft Nordberg crusher had 3mm thickness of hardfacing applied inside out, overlain with another 3mm from the center to the bottom, with an additional 3mm near the bottom (ie a total density of 3mm where stone goes into the crusher, 6mm where crushing is apparent as well as 9mm at the point of discharge). Use was not as bad on the bowl lining, consequently this was treated with a solitary 3mm thickness across its whole surface. The rock being refined was a quartzite with an 85% silica content, a PSV of 65 and also an AAV of 2.
Choose The Right Cone Crusher Liners Manufacturer
Different cone crusher liner manufacturers produce different quality cone crusher liners. Choose the right cone crusher liners manufacturer is the key to prolong the liners span life. Qiming Machinery is the expert in casting cone crusher wear parts liners and OEM for some famous brands crusher.
So the quality is the first!
If you have any other questions,please contact Qiming Machinery.
Comments
Post a Comment