Timely fault diagnosis and intervention
Poor choice of maintenance solutions and sheer negligence have been identified as contributing factors to refractory failure, inevitably resulting into the escalation of smelter operating costs. Verni-Speciality Construction Products offer its technical expertise on cost effective ways of tackling this challenge.
Verni-Speciality Construction Products, a firm that is both a manufacturer and applicator of Refractory Lining Systems, describes the following as possible major reasons for refractory failure:
- Due to non-provision of crucible dimensions with respect to the power input;
- Inferior quality of refractories in size as well as quality;
- Non-adherence to the standard procedures during start up and heating periods;
- Improper control on slag chemistry;
- Poor tap hole management;
- Inconsistency in the operations; and
- Poor electrode management.
Interdependent damage mechanisms
Verni explains that two inter-dependent damage mechanisms that cause degradation in the refractory wall of an entrained bed slagging gasifier, leading to gradual failure and unscheduled shutdown, are either chemical dissolution of the refractory material or fatigue damage from growth of microstructural cracks.
- Chemical dissolution of the refractory material
- This phenomenon is due to penetration of slag through the porous structure of the refractory wall that reacts and chemically dissolves the refractory material.
- Fatigue damage from growth of microstructural cracks Practical steps Predictive maintenance technology“Timely maintenance can make the difference between minor downtime and hundreds of thousands in lost production and costly equipment replacement, significantly increasing business efficiency, a fact both technology providers and mining operators are increasingly aware of,” concludes Vernon Botha, Managing Director.
- Verni’s head office is based in Boksburg, Gauteng. Established in 2001, the company specialises in acid proofing and corrosion protection of concrete, epoxy and polyurethane floor coatings, resin screeds, concrete repair and structural carbon fibre reinforcing, concrete waterproofing, crystal growth systems, bandaging systems and refractory linings.
- With the depressed mining sector performance, Verni says that predictive maintenance technology on refractories can increase productivity and reduce downtime. It warns that, if the refractories are left damaged or left unmaintained, they could cause a huge, costly problem for a high stakes operation.
- Through its technical expertise, Verni offers innovative solutions for timely fault diagnosis and intervention. The company’s suggestions to practical steps that will minimise downtime frequency include reducing bottlenecks which will increase throughput, implementing training, reducing the machine set up time, improving reliability of plant machinery by implementing preventative maintenance, by maximising optimal run rates and capacity and eliminating down time by providing down time reason codes.
- This phenomenon is caused by thermal fluctuations and interstitial pressure that develops from differential expansion between refractory material and the slag. This leads to gradual development of several microstructural cracks inside the refractory surface, which eventually merge together into a single large crack causing rapid failure.