Furnace equipment has been designed by Monometer to operate over a wide range of temperature and humidity, ranging from -40 deg C in Russian winter conditions to + 40 deg C at 100% humidity in parts of Malaysia and India. In addition to the melting furnace, equipment includes filtration, burner control systems and material feed chargers.

Various innovative projects have incorporated Monometer refining equipment, including iron, copper and lead processes, performing significantly above traditional methods in terms of increased yield, thermal efficiency and furnace productivity.

For example, in copper refining from Birch-Cliff to high purity copper, a 6-tonne capacity Monometer tilting rotary furnace will typically cycle in 4 - 6 hours; 3 tonnes of scrap iron may be melted, alloyed and tapped in under 120 minutes, and 10 tonnes lead battery scrap may be processed through the furnace in under 5 hours. Monometer designs and supply includes the furnace charging system, gas diffusion technology for the refining process, slag systems, oxy-fuel burner system, and exhaust filter complete with settler, as well as the fluxing agents injector, and consumable spare parts.

Monometer offers comprehensive onsite support, ranging from turnkey management or installation support, to short training packages targeting metallurgical training or general furnace performance. All Monometer clients benefit from being kept up to date with the latest equipment software updates and full engineering on site support.

For more information on this or Monometer products please contact Dr Christopher Hall PhD, FICME, Monometer Holdings Ltd, Monometer House, Rectory Grove, Leigh-on- Sea, Essex SS9 2HN Tel +44 0)1702 472201 Fax +44 (0)1702 715112

Monometer has continued to develop rotary furnace equipment for the recovery of tin from tin drosses and scrap materials. The most recent installation was installed and commissioned in China in Autumn 2008.

The tin content in the charge materials is within the region of 75% - 80%, with the remainder being made up of caustic cake and other materials including estimated minimum 4% moisture content. A typical overall recovery in excess of 95% metal from the metal bearing content of the materials initially charged into the furnace is achieved in the Monometer rotary furnace

The new installation in China smelts up to 400-kg of charge materials. Reductant and other additive quantities were established and the fuel consumption was approximately 80 litres diesel oil per hour (equivalent to about 85 cub metres Natural Gas per hour).

The Rotary Furnace can also be run continuously to process between 2 and 3 tonnes of Ash in a single cycle. This procedure involves back-charging and part-tapping for short periods of about 20-seconds to discharge up to 100-kg of tin metal from time to time. The advantages of continuous operation with part-tapping and back charging are 1) Losses due to fuming are reduced because the liquid tin is removed from the furnace soon after it has been formed, and 2) the furnace is kept near full capacity which reduces losses and reduces the effective tin loss to the slag.

The process with best results utilises the slag recycling and baghouse dust recycling similar to that used in lead smelting and other similar smelting processes. The return of slag and baghouse dust to the furnace typically achieves an overall recovery in excess of 95% metal from the metal bearing content of the materials initially charged into the furnace.

After-burner equipment is not required with this process; since there are no dioxins, furans, and other combustible products escaping from the furnace exhaust system.

Monometer manufacture a full range of Rotary, Reverberatory, and Crucible melting furnaces as well as electrically heated box and continuous process Mesh Belt furnaces for Heat Treatment applications.

Please contact Dr Christopher Hall or use our contact us form

The Article below will appear in the GIFA show issue of The Cast Metal Times and will be distributed at the exhibition. Written by Dr. Christopher Hall, Director of Monometer. 

TIN, LEAD AND COPPER SMELTING AND RECYCLING WITH MONOMETER ROTARY FURNACES

Monometer rotary furnaces for the reclamation of tin and lead have been in particularly high demand recently, following a significant rise in commodity prices over the past few years, in particular for tin dross processing, for which up to 99.5% of the metal-bearing material in a charge can be recovered as recycled tin. The smelting process is attractively simple and does not involve salt, so the environmental impact of final waste products is low and will typically pass for low cost disposal routes.

 A chrome-magnesite brick ensures long refractory life between lining changes of up to three years, while its high thermal conductivity effects good thermal efficiency by continually passing heat to the charge material as the furnace rotates. The furnace rotation effects a homogeneous heat distribution and reactivity in the charge bed, so the process consumes relatively little reductant, slag volumes are low, and the recovery cycle time is short. For example, the Monometer continuous smelting process operating in a one-tonne capacity furnace will produce up to five tonnes in an eight-hour shift, while the larger of our furnaces at 40 tonnes capacity will typically cycle 80 to 100 tonnes of material over eight to ten hours.

Monometer rotary furnaces are made in the UK to the highest standards of machining and fabrication to ensure reliable alignment of all drive train and furnace rotating components; and all welding, including the integration of spun dished ends, is checked to ASME and/or ISO certification. Following these standards furnace quality is guaranteed, and indeed proven by the many installations worldwide now having achieved in excess of 25 years continuous operation.

The Monometer smelting system extends to accommodate ores of lead, copper and tin, and has been applied in the reclamation of silver from charges of various mixed material. In each of these applications the unique bath depth and rotational programme retain metal fume within the reactive bed of the furnace chamber and effect a rapid cycle and high yield; recoveries of up to 99.5% are quoted in all offers where exhaust dusts are returned to the furnace and this performance is guaranteed subject only to a certified charge assay.

Both low NOx air-fuel and oxy-fuel burner technology are offered with Monometer deep bath smelting furnaces. This is in consideration for the varying needs of diverse processes and client circumstances. In particular, the attractions of the oxygen burner can include a lowering of emissions volumes by up to 75% with an accompanying reduction in the required size of filtration plant, cycle time reduction by up to 40% and reduced metal losses. However, these attractions are attainable for many, but not all processes. For example, a smaller and therefore less costly filtration plant requirement, (which can offset higher oxy-fuel capital costs), is typically only realised where emission volume is reduced by at least 50%, and cycle time is not always influenced significantly by flame temperature alone. This is why Monometer air-fuel systems, having been developed to maximise the heat recovery attainable from vortex recirculation (double pass) principles, remain a highly attractive option for all processes, particularly for tin and lead smelting, and are effective and economical in situations where the necessary oxygen supply is not always available locally at the site of installation.

Monometer offers a fully comprehensive service from design for special applications through to commissioning and continuous assistance after installation. A typical installation will be commissioned and proven by one of our metallurgical engineers to operate to the standards and performance quoted, and our after sales service will attend at short notice regarding any process-related requirements or other furnace needs.

For these reasons Monometer is particularly well placed with the necessary combination of experience backed up by continual development and the highest qualify of manufacture and service, to provide a reliable high performance solution for the client every time.