How quality of clean coal can be improved in spiral concentrator?

In your fine coal washing circuits, achieving a sharper separation means reducing your coal product loss and gaining better yields of low-ash coal. Spiral coal concentrators use the specific gravity of materials with different densities to separate coal, and produce a low-ash coal product at high efficiency.

How does a spiral concentrator work?

How exactly do they work? Slurry is pumped to the upper part of the spiral, which is usually 13′ to 15′ from the floor. From there, it enters a feed distributor, which evenly distributes the feed to each spiral concentrator. Gravity, along with the specific design and shape of the spiral, are the key to making it work.

What is a spiral concentrator?

The spiral concentrator is a modern high-capacity and low-cost device. It is developed for concentration of low-grade ores and industrial minerals in slurry form. The spirals consist of a single or double helical conduit or sluice wrapped around a central collection column.

How does spiral gravity separation work?

Spiral separation uses a flowing film principle based on the size and specific gravity difference present in a mineral suite. In a spiral, heavy mineral concentrate is selectively directed into the spiral trough near the inside of the spiral surface through the use of adjustable product splitters.

Why coal washing is required?

According to industry calculations, coal washing improves the quality of coal by reducing the ash content to 33 per cent from an earlier 40-45 on an average for Indian coal. It also said “washing leads to reduction in the calorific value of the coal as well”.

How do they wash coal?

The majority of coal cleaning processes use upward currents or pulses of a fluid such as water to fluidize a bed of crushed coal and impurities. The lighter coal particles rise and are removed from the top of the bed. The heavier impurities are removed from the bottom.

How does a shaking table work?

Shaking tables are rectangular-shaped tables with ribbed decks with a water film flowing on them. Water flowing along the long axis of the table slurries the fed sample. Low-density particles are transported in the fast-moving film, causing fine, high-density particles to fall into the beds behind rifles.

What are the primary components involved in processing of minerals?

The primary operations are comminution and concentration, but there are other important operations in a modern mineral processing plant, including sampling and analysis and dewatering.

What type of material is separated by using spiral separator?

Spiral Separators are often used in industrial applications such as separating metal abrasives, metal shot, ceramic beads, glass beads and other types of material. Spiral separators operate on gravity only – product is loaded in the hopper, or direct feed tube on a single spiral.

How can we improve the quality of coal?

(1) Improve Heat Rates The higher the ash content of coal, the lower the heating value of that coal . By removing the ash through washing, the coal’s heating value can be improved dramatically . This means that less coal must be burned to produce a comparable amount of electricity .

What happens when you wash coal?

Coal cleaning by ‘washing’ has been standard practice in developed countries for some time. It reduces emissions of ash and sulfur dioxide when the coal is burned. Electrostatic precipitators and fabric filters can remove 99% of the fly ash from the flue gases – these technologies are in widespread use.