The successful Leister distributor, RIKAZ, sells Leister equipment for plastic welding in Kazakhstan. In this blog post, we discuss how Leister’s automatic welding machines are used to weld the geomembranes on large gold mine, tailings ponds. Tight weld seams are also crucial here to ensure that no contaminated water enters into the soil or groundwater.
Things to know about Kazakhstan
Kazakhstan has an area of 2'724'900 km2 / 1'052'084 mi2 and is the ninth largest country in the world. The country stretches from the Caspian Sea in the west to the Altai Mountains on its eastern border with China and Russia. Its largest metropolis, Almaty, is an important commercial hub. Moreover, Kazakhstan is one of the richest countries in the world when it comes to raw materials. Thus, oil and gas production and mining are the country's main sources of income.
44 percent of the total area of Kazakhstan is covered by sand and gravel deserts, 28.5 percent by steppes and forest-steppes.
As you can guess from the thumbnail of this blog post, the tailings ponds of the gold mines are located in the Kazakh steppe. Since there is usually strong winds blowing here, the workers weigh down the geomembranes with sandbags before welding.
Leister’s distributor, RIKAZ, in Kazakhstan
Leister’s distributor, RIKAZ, is a multi-brand trading and service company founded in 2010. RIKAZ offers Leister’s professional equipment for plastic welding, modern geosynthetic waterproofing materials and innovative polymer technologies for industrial and civil engineering in Kazakhstan.
RIKAZ is very successful in Kazakhstan through its distribution of Leister equipment for plastic welding and the matching geomembranes. This is because Leister's high-quality automatic welding machines, heat guns and testing equipment are in great demand in Kazakhstan for civil engineering, especially in mining and quarrying.
Kazakhaltyn commissions RIKAZ to build huge tailings ponds
Kazakhaltyn Mining-Metallurgical Concern JSC (KZAL) is one of the oldest companies in Kazakhstan's gold industry and is known for mining and processing gold ores. The history of the company begins in 1932, after the discovery of gold reserves in the northern part of Kazakhstan. During its heyday from 1970 to 1980, annual production here was six to seven t / 225,055 oz of gold. Over the past 80 years, the company has produced approximately 350 t / 11,252,761 oz of gold.
What are Settling Ponds and What are They Used for?
In the gold mines, gold particles are washed out of the soil. Pollutants, such as lead, arsenic, cadmium or mercury, are released in the process. The water contaminated with these pollutants is collected in so-called settling ponds. By sealing the settling ponds with tightly welded geomembranes, the polluted water is isolated and no pollutants enter the soil or groundwater. The contaminated water from the settling ponds is filtered and then reused. The pollutants left on the ground after filtering, usually trapped in sludge, are then professionally isolated and disposed of.
More than 150 ha or 370.66 ac of geomembranes installed
RIKAZ has installed geomembranes for the soils in the tailings ponds totalling over 150 ha / 370.66 ac. This corresponds to an area of 210 football fields.
Quality Assurance Through Weld Seam Inspection
As mentioned in the previous section, the geomembranes for the settling ponds were overlap welded.
Strong Wind and High Temperature Fluctuations
According to Vadim Shostik, Sales Manager at Leister Technologies AG, it was technically challenging to weld the 1-2 mm or 39-79 mil thin membrane correctly: "Especially the difficult environmental conditions like strong steppe winds and big changes in temperature. They were a big challenge." Under such conditions, it is crucial to carefully match the welding parameters (temperature, speed and joining force) in order to achieve a high-quality weld.
GEO-Technical Sales Engineer, Eddie Weiser, Leister Technologies AG, travelled to Kazakhstan to advise RIKAZ on the selection of Leister automatic welding machines and to assist in setting the correct welding parameters on the GEOSTAR G7 and GEOSTAR G5. In order to guarantee a tight weld, welding must be carried out in the so-called welding window. Read more in the technical article "LQS for Quality Improvement in Geomembrane Projects" by Eddie Weiser on Leister-Stories.
LQS IMPROVES THE QUALITY IN GEOMEMBRANE PROJECTS
The welding work was made even more difficult by the drastic changes in temperature. In summer, the mercury in the Kazakh steppe rises up to 40°C / 104 °F during the day. At night, the temperature hovers around freezing. Such temperature fluctuations have an effect on the quality of the weld seam. This is because when it is cold at night, the geomembrane contracts, which puts about twice as much stress on the weld seam as when it expands in the heat of the day.
Unfortunately, anyone who thinks that the welders had it easier in the winter is mistaken. In winter, the temperature here is -20°C to -30°C or (-4°F to -22°F) at night and still rises above freezing during the day. In addition, the onset of winter in this region is often very sudden, so quite different from what we know in Switzerland, for example.
Which Leister Equipment was Used?
RIKAZ employees were welding details such as this T-joint with Leister’s WELDPLAST S2 manual extrusion welder.
Here is a list of Leister’s automatic welders, extrusion welders, heat guns, and testing equipment that RIKAZ has used to seal the settling ponds:
RIKAZ and Leister have been working together with a successful partnership since 2013
Vadim Shostik sums it up: "RIKAZ is very successful in Kazakhstan and is considered a reliable partner throughout Central Asia. As far as our cooperation is concerned, RIKAZ is a one-stop shop: Service, technical support, user training, repair services and spare parts. What Makes our Partnership Great RIKAZ actively helps us test new developments. RIKAZ recently tested a new set of rollers for the Leister TWINNY T5 and TWINNY T7 automatic welding machines. This was done under rough conditions. The feedback has been positive, by the way."
We’d like to thank RIKAZ for a successful partnership and for their great cooperation. We look forward to completing many other exciting projects together in the future.
Author: Silke Landtwing, Manager Corporate Communications, Leister Switzerland
LEISTER’S DISTRIBUTOR, RIKAZ LLP, IN KAZAKHSTAN
KAZAKHALTYN MINING-METALLURGICAL CONCERN JSC (KZAL)