A common operational challenge associated with solvent extraction (SX) plants is the effective on-line management of solids. Solids are either often carried over from leaching circuits, are formed as a result of chemical precipitation within the SX circuit or electrowinning (EW) operation or enter the circuit via external means (dust). Solids in SX settlers and EW cells reduce plant availability and name-plate design capacity.
Most existing crud and bottom solids removal systems are limited in their effectiveness and operations are often forced to take the impacted settlers off-line for complete removal of solids. These cleaning operations are hazardous, high risk, labour intensive and costly in terms of production down-time and organic reagent loss. Due to production pressures, operations are often reluctant to take settler units off-line, resulting in prolonged operation at below-optimum performance. This often compromises the final metal production rate, product purity and reagent consumption rates.
The Crud Cobra is a solids removal specifically designed for the on-line removal of entrained interface solids associated with hydrometallurgical SX processes.
The system can be used for on-line SX-settler interface crud removal, eliminating the need to interrupt operation. Plants using the system, in conjunction with the Crud Forx™ SX settler bottom solids removal technology, have enjoyed prolonged periods of operation without the need to drain settlers for cleaning.
The Crud Cobra consists of a wide suction head mounted on a riser pipe connected to a sled. The crud section head can be adjusted to various positions along the riser pipe to accommodate the various operating interface levels of the client’s SX settlers. The crud section head can either be connected directly to a removable flexible hose coupling, or to one or more modular lengths of rigid transfer piping. The Crud Cobra and accessories are available in a variety of materials of construction, suitable for use in most hydrometallurgical environments.
The Crud Cobra requires a typical crud removal displacement pump system generally included in most SX settler designs. The unit can be easily adapted for retrofitting to most crud removal positive displacement installations. This makes the units inexpensive to install and operate.