The gold mine in North Mara is situated in the north-west of Tanzania, at about 100 kilometres east of Lake Victoria and 20 kilometres south of the border with Kenya. The gold mine works an average of 8,000 tonnes of minerals a day and produced 287,188 ounces of gold in 2015. The gold mine has two deposits: one underground in Gokona and an open mine in Nyabirama. For the former, a flexible high-performance machine was required that was able to produce the concrete necessary for strengthening the walls of the entrance tunnels, thus avoiding the detachment of debris. The difficult terrain, with steep slopes, required a machine that could operate under extreme conditions. Moreover, the concrete had to be of the highest quality for use in the very difficult conditions of mines. The Carmix solution chosen by the customer was Carmix 5.5XL, a model that combines easy manoeuvring with high output in situations that require power, versatility and precision.
Carmix 5.5XL is the ideal combination of what the company offers professionals: an independent concrete mixer system that produces large quantities of concrete directly at the worksite. The concrete mixer unit has a capacity of 7,600 litres, with an effective output for the mix of 5.5 m3. Inside it, a system with a double mixing blade, a drum with hydraulic rotation and a planetary reducer provide a uniform and compact mix. This result is also achieved thanks to an automatic loading system, which, with the aid of the front cab, next to the loading shovel, allows maximum visibility for operations. Control and monitoring tools play a key role: Carmix 5.5 XL is fitted with Joymix, a servo-controlled joystick that controls the hydraulic functions of the loading shovel and allows the concrete to be discharged up to two metres in height. In addition, an optional Load Cell weighing system is available, with load cells under the concrete mixer unit, for producing high-quality concrete.
Like the entire Carmix line, this model also comes in simple design for operators, where every component meets the operational needs of professionals. For example, four-wheel steering facilitates manoeuvring in restricted spaces, thus optimizing movements. In addition, the Perkins 112 kW motor with six water-cooled cylinders and an integrated four-wheel drive system ensures the power required to work at difficult worksites, with gradients of up to 30%. The particularly tough conditions of the terrain at the gold mine and the challenging access routes required flexible machines that are able to tackle very steep climbs and descents while carrying a full load