Another Develon DX1000LC-7 for KTT
Estonian operator takes delivery of second 100-tonne crawler excavator for use in oil shale mine
FOLLOWING on from the purchase of the first Develon DX1000LC-7 100-tonne crawler excavator in Europe, Estonia-based Kiviõli Keemiatöötus (KKT), part of the Alexela Group, have now bought the company’s second DX1000LC-7. As well as joining the existing machine, the new DX1000LC-7 excavator is working alongside 80-tonne Develon DX800LC-7 and 50-tonne DX490LC-7 models already working at KKT’s oil shale mine at North Kiviõli in Estonia.
Like the first excavator delivered at the end of January 2023, the new DX1000LC-7 has been supplied by INTRAC Group, Develon’s authorized dealer for the Baltic countries of Estonia, Latvia, and Lithuania.
The decision to replace one of the other brands of 80-tonne machines used on site with the DX1000LC-7 was based on the successful performance of all three Develon machines, with which KKT are burning far less fuel than the competitive machines, for the same production output. The first DX1000LC-7 has already completed well over 13,000h of operation in only two years and five months, operating 15h days faultlessly throughout the 29 months it has worked at the North Kiviõli oil shale mine.
The second DX1000LC-7 promises even more efficiency gains. Equipped with a 6.8m3 bucket and driven by the most powerful engine in the 100-tonne class, the excavator also has the highest hydraulic flow for this size of machine, providing best-in-class performance, with higher productivity, lower fuel consumption, and smoother controls.
The DX1000LC-7 excavator is powered by a well-proven Stage V diesel engine, providing a high power output of 469kW (629hp), more than any other machine in this class. The high output of the engine is combined with a virtual bleed off (VBO) hydraulic system (D-ECOPOWER+), providing a best-in-class hydraulic flow of 1,569 litres/min (3 x 523) and a high system pressure of 360 bar, together contributing to the best performance in the 100-tonne market.
More than 100 years ago Estonia discovered that stone at the North Kiviõli mine contained oil and from that time onwards started to extract it. The process used to obtain the oil remains unchanged. First, the stone is extracted once the overburden has been removed – around 8m3 of overburden have to be removed to provide around 1m3 of oil shale.
Different techniques are used to remove the overburden. The first involves blasting and loading trucks with the 80- or 100-tonne excavators. Another uses a 50-tonne excavator equipped with a breaker and one of the larger excavators for loading trucks. The third method employs an 80-tonne excavator equipped with a vibrating hydraulic ripper (Xcentric) and another 80-tonne excavator equipped with a bucket to load trucks.
Different techniques are also used to extract the oil shale. These include direct use of an excavator to load a truck, or the use of a surface miner to extract the material, crush it, and load it into a truck. The transformation process to produce oil from the stone begins with the stone being crushed and then loaded into a reactor unit, where it is heated to between 400–800°C depending on the size. As well as oil, phenol is removed from the stone. Overall, the process takes around 2h. Generally, a kilogram of stone contains 20–30% oil and KTT are moving around 10 million tonnes per year (overburden and oil shale).
Estonia’s oil shale industry is one of the most developed in the world. The National Development Plan for the Utilization of Oil Shale 2016–2030 describes the material as a strategic resource. Indeed, Estonia is the only country in the world that uses oil shale as its primary energy source. In 2018, oil shale accounted for 72% of Estonia’s total domestic energy production and supplied 73% of the country’s total primary energy. About 7,300 people (more than 1% of the total workforce in Estonia) are employed in the oil shale industry.
