LUM-Series Ultra fine vertical grinding mill is professional suitable for a variety of non-metallic mineral grinding and classification, the large-scale project plant desulfurization limestone powder grinding, deep processing of slag powder and preparation of pulverized coal injection, etc. large-scale projects. It can one-time to meet customer requirements for fineness and yield.

• Capacity: 5-18 ton per hour
• Out put size fineness: 400-650 mesh
• Ultra-fine powder through sieve rate: over 90%
• Application Case: grinding ceramic case, grinding slag superfine, grinding fine cement, grinding gypsum superfine, etc.

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Two VM1900 vertical mills were sent to Russian customer’s site. On Nevember 28,two VM1900 vertical mills of Kefid were successfully sent to the Russian customer’s site. This shipment task is urgent.With the support of production and quality department, the customer center finally timely ensure the smooth delivery of the product. Kefid adhere to “provide customers with higher returns” To this end, customer center supply many powerful guarantee in delivery time and technical support for customers.

VM Series vertical mill is the large grinding equipment that Kefid developed to solve industrial mill’s output low energy consumption and higher technical problems and absorb European advanced technology combined with many years of mill design and manufacturing philosophy and market demand. The equipment is set crushing, grinding, drying, classifying, upgrade in one. It has the features of small floor area, simple process, high grinding efficiency, low energy consumption, low noise, large drying capacity, product fineness easy to adjust, no dust pollution, easy maintenance, reliable operation,etc.It is very suitable for large-scale grinding process, the main technical and economic indicators have reached the international advanced level.

If I assume that you are doing complete VRM maintenance cycles e.g. exchange of the classifier rotor, the grit cone, exchange and optimization of the static flaps, exchange of housing liners for mill and classifier, refurbishing the louver/nozzle ring etc – in short all jobs that are included in the thorough maintenance cycle of a VRM – then I would be interested in some more in-depth discussions, especially your experience with the time cycle needed for the high-velocity = high wear areas between dam ring and mill housing.

In case of your opening argument referring only to the re-welding/re-surfacing of the grinding elements …rewelding of the grinding elements is an annually or bi-annually standard procedure. Without the refurbishing of the grinding elements (or the exchange with new tires / table liners) the production of a VRM will drop to app. next to nothing.
Therefore I am not sure where you got the 100% lifetime extension?
The typical lifetime that I would expect out of a vertical mill is between 20 and 30 years – by performing the regular rewelding of the wear parts / grinding elements this is not extended to 40 or 60 years.
Or do you refer to the lifetime of the roller tires / table liners?
in this case we want to discuss the costs of annually or bi-annually rewelding (including mobilization costs, transport costs of the welding gear etc..) versus the costs of an exchange with new roller tires. As an average the lifetime of a roller tire can be extended by app. 3 times through proper and timely rewelding (300 % lifetime extension) but is this economically wise?
Both methods (welding versus exchange) are in competition with each other and it strongly depends on the local circumstances (material abrasiveness factor, wear progress per runtime and tonnage = required frequency of welding versus costs of welding versus costs of new tires) and vary greatly on a case-to-case basis.

The re-welding of roller tires outside of the VRM typically has been proven to be as expensive as a new tire – only a new tire comes with certain guarantees that usually are not given for any re-surfacing. On the other hand – a well equipped on-site workshop might be up to the external re-welding at reasonable costs, as long as the in-house experience is available.

Vertical mill is a large grinding equipment based on years concentrated design and development by introducing advanced European technology and years design and manufacturing experience and market demand of Kefid to solve the problem of low production capacity and high power consumption of traditional grinding mills.

Vertical roller mill has adopted reasonable and reliable structure design acting in concert with advanced process which is integrated by drying, grinding, powder separating and elevating, which is able to meet clients’ need well with internationally advanced technological and economical indexes and can be adopted in cement, hydroelectric construction, metallurgy, chemical, and non-metal ore grinding, especially in large scale grinding or various ores of lump and grain shape into powder.

Vertical Mill Features:

1. Low operation cost
(1) High grinding efficiency. Vertical mills grind material through grinding between grinding rollers and material bed with 40%-50% less power consumption comparing with ball mill, which will be more obvious while moisture is increasing.
(2) Less metal wear. Liner and rollers are made of special material which enables longer life, less operation cost and higher utilization.
(3) Outer loop device is equipped to reduce power consumption further.
(4) Larger feed material size which can be 5% of roller diameter, generally ranges from 40 to 100mm. And by using medium and large models, there will be no need to use secondary crushing system.
2. Lower Construction Cost. Land occupation and construction area can be 50% less comparing with ball mill system reducing construction cost by about 70%.
3. Simple and stable operation.  Automatic control system is equipped to enable long distance control and is simple in operation.
4. Powerful drying ability. Vertical mills adopts air stream in material conveying. During grinding of material with higher moisture, wind temperature can be controlled so as to repair final products to meet moisture requirements, which is up to 12% to 15% in vertical mill, which can only be 3-4% in drying ball mill.
5. Stable products quality and even products shape. Material will stay only a short period in the mill making inspection and control of product grain size and chemical composition easier and quality of products more stable.
6. Easy in maintenance. Maintenance can be completed by maintaining oil cylinder, turning moving arms, rollers, liner quickly.
7. Environmental friendly and low in power consumption. There will be light vibration, small noise, small amount dust, clean operating environment, which can meet environment protection requirement well.

Technical Parameter :

Mm to inch conversion: 25.4millimeters=1 inch
The humidity and hardness of raw material will affect the fineness and capacity.

Ore Mill:

Notes:
1. Material should be with hardness less than 7 in Mohs’.
2. Hot air is only necessary if outlet moisture is required to be less than inlet moisture.
3.When grinding material is difficult to grind, please use the largest power.

Coal Mill:

Note: Any change of VM Vertical Mill technical data shall not be advised additionally.