3.2 New Smelter Cladding Saves $Ms in Downtime
Our client operates a poly-metallic underground mine in SA. The integrated mill, smelter, refinery and mine is a complex operation where capacity of all elements in the flow sheet are balanced to optimise overall efficiency.
The smelter is a core process and maintenance downtime costs $ millions in lost production value. The cool down and reheat each takes more than a day, so maintenance events are well planned up to a year in advance.
It not only produces copper, but other base and precious metals plus sulphuric acid from copper sulphite ore that is mined in South Australia. Operation of smelters have many issues; hot metal handling, acid dust and gas handling, foaming into the waste heat boiler and waste heat boiler tube failures.
Engineers identified LaserBond for our ability, and technical know how, to develop and apply a corrosion and erosion resistant metal cladding to the copper (CFM) cooling elements of the smelter and also protect the boiler tubes in the waste heat boiler at the smelter.
Problem
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The dust laden hot furnace gas very abrasive and corrosive resulting in aggressive ablation of the copper cooled gas handling equipment. As coolers wears, the cooling profile changes resulting in more build up of dust accretion and increased corrosion, this then leads to a cooler being compromised and the danger of a water leak into the furnace with the resultant steam explosion.
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In an attempt to extend cooler life, operators had previously tried a number of different options; stainless steel metal tiles, ceramic refractory cladding, and cooler redesign, all of which failed in about 12 months well short if the planned cooler life cycle.
Solution
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Engineers identified LaserBond for our ability, and technical know how, to develop a metallurgy and application method to affix a durable corrosion and erosion resistant metal cladding to the copper (CFM) cooling elements of the smelter and also protect the boiler tubes in the waste heat boiler at the smelter.
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The top leading and trailing arch of the copper cooled furnace off gas equipment was laser clad with a high wear and corrosion resistant material selected for this hot corrosive and abrasive environment. This enabled the furnace off gas equipment to maintain its diameter and integrity many times longer than uncoated and unprotected OEM parts.
Benefits
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Operating efficiency of copper cooled gas handling equipment enabled the furnace to run longer, between shutdown campaigns, it ran for almost 3 years (vs 1). Each shutdown costs at least $18M in lost production.
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Extended dimensional integrity of the LaserBond® clad copper cooling elements allowed for better furnace sealing, greatly reducing air intake which directly influences the increased life of downstream waste heat management system.
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Cost savings over multiple OEM replacement parts.
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Furnace availability improved with less downtime for inspections and maintenance.
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Better outcome for environment; less waste,
Feedback
LaserBond‘s science and innovation came through! Their cladding development offered a better than new replacement part at a fraction of the cost.
Engineers recommend that all next generation gas handling equipment will now be LaserBond® clad with further cladding to be applied to downstream waste heat handling equipment.
Further applications to actual in furnace copper coolers are being investigated.
