Grinding and Ore Processing

GRINDING PROCESSES
Sever Minerals supplies equipment by Metso, the world’s leader in mineral processing. We use the world’s most extensive family of mills and package grinding and ore processing systems for miners.

Engineers in Sever Minerals are ready to implement projects of any complexity using the most efficient and energy efficient equipment under long-term technical support.

Autogenous mill / Semi-autogenous mill
Autogenous uses the milled material as grinding media. Semi-autogenous milling additionally uses supplemental grinding media (the most common are steel balls). AG/SAG mills by Metso are ideal to mill runoff mine ore or primary crusher product. This mill line includes different sizes and powers:

  • Geared mills
  • Gearless mills
  • Mills with a sleeve bearing or a hydrostatic bearing
  • Frame- or trunnion supported mills

As they enable processing of clay and wet material, SAG mills are often used to prepare material for grinding by ball mills.

Ball mills and pebble mills
Ball mills use metal grinding media, pebble mills use ceramic of natural stone grinding media. Pebble mills are often used for single-stage fine grinding.

Rod mills
These mills use rods as grinding media to ensure evenly sized product output. Out-of-size material and unnecessary fraction production is minimized. Such mills are usually operated as first stage before ball mill or pebble mills to grind metal ores, hard coal/coke and other materials in dry or wet grinding. Materials with too high humidity or highly dusting during fine grinding and dry sorting can also be grinded in a rod mill.

Stirred mills
There are two main stirred mill types — gravity-induced mills and fluidized mills. Sever Minerals supplies both these types, and ensures unparalleled performance and operation availability of fine grinding and ultrafine grinding:

VERTIMILL are gravity induced vertical mills. They feature high energy efficiency, low consumption of grinding media, convenient installation and safe operation, and are the most cost saving solutions for many processes. VERTIMILL can grind feeds as coarse as 6 mm to finer than 20 micron,

Stirred Media Detritor (SMD) is a fluidized vertical stirred mill designed for optimum grinding efficiency for fine and ultrafine products. SMDs feature simple design and do not require frequent maintenance to ensure the highest operation availability among commercially available grinding equipment. The mills are particularly efficient to grind <20 micron products. In combination of low cost and moderate grinding media consumption it ensures the lowest costs of ultrafine grinding.

ORE PROCESSING
Processing and dewatering of feed require efficient and reliable process equipment such as flotation machines or magnetic separators, settlers and filters. Sever Minerals uses the best processing and separation processes which ensure high process efficiency and low operation costs.

RCS flotation machines
Metso RCS flotation machines have the most state-of-art design which combines all benefits of reactor cell with the unique features of rotor/stator mechanism (pulp aeration) to maximize performance of maximum efficiency of roughing, intermediate, scavenging and cleaning duties.

The new improved DV (Deep Vane) flotation design improves air dispersion and bubble size distribution. The patent-protected DV impeller consists of a unique arrangement of vertical vanes with shaped lower edges and air dispersion shelf. The mechanism design produces powerful radial slurry pumping to the cell wall and gives strong return flows to the underside of the impeller to minimize sanding.

DR flotation machines
DR flotation machines are ideal for small concentrators and industrial minerals. They are designed as rectangular chambers with a partition with a material flow port. Overpressure increases effective aeration area, and vertical pulp recirculation keeps solid in suspension and prevents sanding of the cell bottom.

Flotation columns
Flotation columns ensure high recovery and performance through the unique sparger system which reduces bubbles to optimum size: a flow of smaller bubbles maximizes saturation with valuable component in the machine surface and increases its throughput.

Magnetic separators
Sever Minerals has a vast experience with magnetic separation technology and supplies different types and sizes of separators to address any production goals.

  • Hugh gradient magnetic filters (HGMS)
  • Cyclic equipment with a 220 to 3050 mm tank
  • It is a continuous equipment with a 1200 mm, 1850 mm, 2500 mm and 3500 mm matrix
  • Low intensity magnetic separators (LIMS): wet magnet separators for recovery of dense media have a 1200 mm and up to 3.6 m long tank.

DEWATERING
Sever Minerals provides clarification and dewatering technologies for wastewater and process water which minimize adverse effect on environment from production activities. To address this, we offer a number of dewatering and filtering solutions.

Inclined plate settlers
Inclined plate settlers use several parallel inclined plate packs to maximize settling area to reduce settler floor space (up to 5 times) and reduce production room area. It allows to reduce dimensions and costs for installation of a lamella settler saving the pre-set clarification and thickening parameters case-by-case.

Two main criteria to evaluate sedimentation equipment are clarity of overflow and maximum density of the underflow solids discharge.

The area needed to thicken pulp increases as settled product coarseness reduces. Since it is an global trend to reduce coarseness of feed for processing, cylindrical settlers with rake mechanism can be unnecessarily large.

Metso plate settlers have been of interest recently especially in potash industry where we have vast experience of successful installations.

Vertical Plate Pressure Filters VPA
Environmental awareness has been the major driving force in the rapid development of the filtration and dewatering technology. Also increasing energy and personnel costs have made tougher demands on efficiency and automation of processes. According to these demands, for minimum, Sever Minerals supplies VPA pressure filters family which combines high reliability, easy maintenance, stable fully automatic productivity to reduce general costs of filtration.

Automatic vertical plate pressure filter VPA has the following unique features:

  • Light weight construction with machined polypropylene filter chambers,
  • Compact design with pulling hydraulic cylinders for reduced space requirement,
  • Filter chamber design makes filter cloth change a one-minute operation,
  • Available in several pressure ratings for different applications,
  • Few moving parts for low maintenance and high availability,

Spiral dewaterers
Spiral dewaterers SDC is a robust evolution of spiral classifier, and is used to dewater coarse material, e.g. mill scale.

Spiral dewaterer with a special design spiral and enlarged pool area is able to handle large flow of effluents offering a dewatered scale product and overflow (typically 100 ppm).

The spiral dewaterers are used to:

  • Dewater scale in continuous casting, hot rolling and scarfing,
  • Dewater coarse material.

Tube presses
Tube Presses by Metso are fully automatic hydraulic tube presses which operates at up to 140 bar. It is designed to filter extremely fine particle slurries, producing a filter cake of very low moisture content in comparison with other forms of commercially available dewatering equipment. High pressure gives a higher degree of separation of the liquid and solid phases.