The new excavator has joined the existing Doosan DX800LC-7 and DX490LC-7 models already working at KKT’s oil shale mine at North Kiviõli in Estonia, where the company also operates a number of other 80t excavators. The purchase decision to replace one of the existing 80t machines with the new DX1000LC-7 was based on the successful performance of the DX800LC-7, which Doosan says uses 10l/h less fuel than competitive machines, for the same production output.  Doosan states that the savings add up as after over 4,000h, the DX800LC-7 had already saved the equivalent of 40,000l of fuel. Doosan states that when compared to the other 80t excavators, the DX800LC-7 uses €1.5l less fuel, saving €60,000 after only 4,000h. After 10,000h, the saving will be equivalent to €150,000.

Even greater savings

Doosan says that the new DX1000LC-7 promises even more savings. Driven by what the company claims is the most powerful engine in the 100t class, the DX1000LC-7 is also said to have the highest hydraulic flow for this size of machine, delivering, what Doosan says is higher productivity, lower fuel consumption and smoother controls. It is also equipped with a 6.8m3 bucket. The DX1000LC-7 excavator is powered by the new stage V version of the Perkins 2806J diesel engine, providing a power output of 469kW. The high output of the engine is combined with a ‘Virtual Bleed Off’ (VBO) hydraulic system (‘D-Ecopower+’), providing a hydraulic flow of 1,569 l/min and a high system pressure of 360bar.

Dating back over 100years

Estonia discovered more than 100 years ago that the stone at the North Kiviõli mine contained oil inside and from that time onwards started to extract it. The process to obtain the oil remains unchanged. First the stone is taken out, and after around 8m3 of overburden is removed this provides around 1m3 of the precious oil shale. To remove the overburden, different techniques are used. The first involves blasting and loading trucks with the 80t or 100t excavators. Another uses a 50t excavator equipped with a breaker and one of the larger excavators for loading trucks. The third method employs an 80t excavator, equipped with a vibrating hydraulic ripper (‘Xcentric’) and another 80t excavator equipped with a bucket to load trucks.

After removing the overburden, the extraction of the oil shale starts, again using different techniques. These include direct use of an excavator to load a truck or using a surface miner to extract the precious material, crush it and load it into a truck at the same time. 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 400o to 800o depending on the size. As well as oil, phenol is also removed from the stone. Overall, the process takes around two hours. Generally, a kg of stone can be 20% to 30% comprised of oil and the mine operator is moving around 10M/t per year (combining the overburden and oil shale).

Primary energy source

The oil shale industry in Estonia is one of the most developed in the world. The National Development Plan for the Utilisation of Oil Shale 2016–2030 describes oil shale as a strategic resource. 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 Estonia's total primary energy. About 7,300 people (over 1% of the total workforce in Estonia) are employed in the oil shale industry.

Dealer support

Intrac is solely responsible for sales and servicing of the Doosan crawler, wheeled and mini/midi excavator, wheel loader, articulated dump truck and attachment ranges in Estonia, Latvia and Lithuania.

Intrac’s sales and service centre for Latvia in Riga is highly regarded in the Baltic region. The company also has facilities at its branches in Vilnius and Tallinn, which are the focal points for the service provided in Lithuania and Estonia respectively. In total, Intrac has 13 outlets with workshops and 55 fully equipped service vans in the Baltic region. Intrac customers benefit from onsite service networks, covering everything from emergency repairs to routine maintenance. The company’s factory trained engineers have many years of hands on experience of repairs and servicing of plant and machinery.