Briquetting product shapes

More than one kind of dryer may be applicable to a particular product, or the shape and size may be altered to facilitate handling in a preferred kind of machine. Thus, application of through-circulation drying on tray or belt conveyors may require prior extrusion, pelleting, or briquetting. Equipment manufacturers know the capabilities of their equipment, but they are not always reliable... 

The reciprocating movement of the piston(s) and the relatively small volume of the die cavity severely restrict the capacity of this type of equipment even if modern, multistation, rotary tabletting presses are considered. With the production of larger pieces in, for example, hydraulic presses or roller briquetting machines, the accuracy in weight, shape, and dimensions is no longer obtained. 

Neither of these extreme situations is feasible. For case 1 no practically conceivable cup shape could produce equal strain increments and in case 2 a material with the necessary degree of plasticity would normally be incompatible with a potential need to develop adequate pressing load because the material could be extruded from between the pockets at relatively low pressure. Alternatively, the product specification may exclude modification of the material or it is impossible to remove the plasticizing constituents after briquetting if... 

Before continuous ice makers for the quick production of cubed ice became available, this binding mechanism was used in large commercial ice production plants to recover undersized ice or shape fines into small pieces by ice briquetting. More re-... 

Based on this and other success stories and the need to conserve raw materials and avoid waste (Chapter 8), other, particularly non-ferrous, materials are collected and converted into high-density shaped products (briquettes) by pressure agglomeration techniques. The aim of the briquetting process is to obtain similar characteristics to those listed in Tab. 6.9-2. 

Another new application of coal briquetting that is already being used, is the den-sification and shaping of solid reductant for the direct reduction of iron ores. Such briquettes are mixed with iron ore and fed into the reactor where controlled combustion provides heat and reducing gas for the production of direct reduced iron (DRI). 

The most common agglomeration technology for the conversion of sodium cyanide into a safe product is briquetting with roller presses. Almond- or pillow-shaped compacts are made. The systems are completely enclosed, equipped with highly effective dust collection systems to safeguard the operators, and executed in stainless steel to keep corrosion in check. The discharge from the roller press is screened within the enclosed system, fines are recirculated internally to the briquetter feed bin, and dean product is immediately packed into sealed containers. 

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