Mining can sometimes turn into a veritable minefield for companies. Rising cost of operation, wastewater disposal and unpredictable demand take their toll on the mining sector and its neighbours. On the other side, mining offers a perspective one can rely on: a major part of the resources for modern day technology is mined. Mining is also essential for supplying power.
From Vattenfall Europe's view of things, coal has to be good. The utility company mines over 60 million tons of brown coal annually, to supply its power plants with fuel. Worldwide a billion ton of brown coal is mined each year. Countries such as the USA, China, Russia countries in Central, Eastern and Southeast Europe are pushing coal mining.
Germany is also still placing its bets on the brownish, blackish soft sedimentary rock. According to trade association Arbeitsgemeinschaft Energiebilanzen 2013 saw the highest level of power produced in ignite-fired power plants since the German Unification in 1990: with 162 billion kilowatt hours electricity the amount was 0.8 percent higher compared to the year before – despite renewables becoming more and more relevant. Countries such as Poland, the Czech Republic, Greece and Bulgaria also have a high coal share in their power supply. And there is no end in sight. The conveyor belts won't come to a standstill.
Filled order books
It is quite clear the mining industry will fill the order books of various valve manufacturers. Take Brandenburg and Saxony, for instance: here, Vattenfall Mining AG operates five open-cast mines, in order to turn brown coal into electricity. Coal mining requires dewatering and lowering of groundwater through numerous deep wells, as well as draining it off to mine water treatment plants. Air valves make it possible that small air pockets can be continuously discharged while maintaining operating pressure. In the case of pump failure or fast closing of shut-off valves an air valve can feed in an unsimilar larger amount of air into the piping. This ensures that the thin-walled PE pipe doesn't implode and is kept safe from hydraulic shocks. Mankenberg benefitted – the company supplies Vattenfall with air valves.
Mankenberg's automatic air valves are deep-drawn and made from stainless steel panels. A major requirement for a valve to meet the demands of mining. The valves have to resist acidic, corrosive water and outdoor temperatures of up to minus 30 degrees Celsius. This can't be done without frost protection and low-maintenance operation.
Control valves keep the transport of slurries in check – powdered ore enriched with water and chemicals. “Positioners control the function of cylinders ‘dart valves’ and dampers in the flotation cells,” explains Jürgen van Santen, Samson AG's PR manager. In smelting, control valves monitor the flow of thermal oil, oxygen and air. “A very special area of application for valves with ceramic lining is pulverised fuel ash, which is created during smelting”. Valves need chemical resistant lining for solvent extraction.
Uses for all sorts of valves
“In mining processes, all valve types from gate valves to valves from the most extreme conditions in high- and low-temperature applications, as well as for high pressure levels, are used,” van Santen summarises.
For Samson as a company the mining business has developed positively. “In the mining business, mining of copper, lithium and zinc is a growing segment for us”. An example: in copper and metal mining processes adjustment valves are increasingly being used, a product spectrum in which the company has been developing and manufacturing high-specialised process valves for over 100 years.
Lots of mines are located in dry desert regions, where seawater desalination serves as an alternative to use of regular service water. In order to meet the requirements a special valve without auxiliary power was developed, explains van Santen, to control the water flow in the ring pump.
The mining industry can't afford process interruptions. In conventional applications linear drives with external path measurement sensors and positioners control opening and closing of dart valves, which regulate the upper foam level and thus the metal concentration of the ore. External sensors are risky, as they are extremely prone to failure and malfunction in the dusty and muddy environment. In addition, the sensors can easily be readjusted by mistake and need to be recalibrated. “That costs time and money, as the plant has to come to a standstill for such service purposes,” reports automation company Festo. A cylinder tube that securely and compactly encloses all components can offer relief. Each flotation cell ought to be fitted with a control enclosure, states Festo. This is put into practice in the Mexican silver mine Fresnillo, the oldest silver mine on the American continent.
Keeping employees safe
It is without question that requirements for process components used in mining are high. The industry expects „higher performance for mining and processing of metals and minerals“ from its suppliers, emphasises Pentair Valves & Controls. Service costs for maintenance and repairs need to be lowered, performance and lifetime of plants and pipes need to be increased. Employees also need to be kept safe. In addition, components have to be dependable in regards to adhering to environmental regulation and quality standards.
Therefore “various valve types as well as versions made from special materials such as Hastelloy, duplex, Monel for casing, seating and disc are necessary in mining,” states Samson's van Santen. Furthermore the trend is towards online diagnosis through a positioner monitoring the function of a valve and making it possible to pre-emptively warn of unexpected failure. The requirements of the mining industry towards higher automation of processes and demand for valves with communication capabilities in a process have to be fulfilled.
All of this is taking place while the mining industry is facing challenges: in the last few years, there have been in some cases huge cost increases for consumables such as fuel, water, truck tyres, cables and grinding balls and energy. In addition, costs of labour rose. Rate of return has diminished – volumes grew while yields decreased. “Moreover industry investments have been sluggish because of higher costs for mining rights and local rates, stricter environmental regulation and long-winded authorisation processes,” explains van Santen. In addition, new mining areas are located in geographical locations difficult to access, such as mountains, deserts or in nature reserves. To make matters worse, there is a shortage of qualified labour.
Nonetheless, a lot hints towards a favourable outlook for the mining industry. “The industry continues to have a high demand for cables, pipes, circuit boards and batteries, which require copper and other metals,” states van Santen. A good economic recovery and positive growth forecasts for the world economy drive demand. In China, demand for copper and metals will remain high.
Challenges as opportunity
Even mines that have been closed offer opportunities. They require environmentally sustainable action, ecological conditions needs to be restored. New technologies are needed. Innovative industries – like those in Germany – can also become strong partners for transferring technologies.
Presse Kontakt Valve World Expo 2014:
Kathrin Kleophas van den Bongardt
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