Spiral chute concentrator

Spiral chute concentrator structure and working principle

The structure of the spiral chute concentrator is shown in Figure 1. It is made the spiral by a bending chute around the vertical axis, the spiral has 3 to 5 circles, fixed on a vertical support, the spiral groove section is a parabolic or elliptical part, the bottom of the groove in the longitudinal (along the direction of the flow of ore) and transverse (radial) have a certain degree of inclination.

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Gravity Separation

1. Introduction

Separation by density difference is a process that is as old as recorded history. Separation of gold by density difference dates back to at least 3000 BC as depicted in writings from ancient Egypt. The principle employed in gravity separation goes back further in time to the formation and weathering of the rocks and the releasing of the minerals they contain and the transport of the mineral grains by heavy rains. It is the driving force for the formation of the alluvial deposits of precious metals and gemstones that have been worked since beyond recorded history as they still are today. Archaeological excavations have discovered mineral concentration activities such as the lead–silver concentrating plant in Attica, Greece, dating from 300 to 400 BC. So gravity separation has a long history as a mineral concentration process.

Not all mineral combinations are amenable to this type of concentration technique. To determine the suitability of gravity separation processes to a particular ore type, a concentration criterion is commonly used. A concentration criterion (CC) can be defined as

where SG = specific gravity (or density), and the fluid is typically water or air.
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