he hydraulic engineering mining splitter has large splitting force, small volume, light weight, convenient operation, no vibration, no noise and no dust during work. In the

 

process of removing the cathode carbon block and furnace lining during the overhaul of the electrolytic cell of the aluminum plant, the effect is significant, highly efficient, environmentally friendly. This paper discusses the working principle, technical performance, instruction, specific application and effect evaluation of the hydraulic splitter.

 

Currently, the life of the electrolytic cell from domestic electrolytic aluminum factory the is generally 1,100 to 1,500 days. That is, after 3 to 5 years of use, the cathode carbon block of the electrolytic cell will be eroded by the electrolytic melt, the cathode pressure will increase, the energy consumption will increase, and even the electrolytic cell will be damaged, which will greatly reduce the yield and quality of the original aluminum. Therefore, it is necessary to periodically overhaul the electrolytic cell: remove all the cathode carbon block and the groove lining, and build the new cathode carbon block and groove and the inner lining. The cathode carbon block undergoes long-term high temperature and pressure, which will produce complex chemical and physical changes. It is sintered, ceramized, alloyed, and become abnormally hard. They will adhere to each other, which is difficult to dismantle than reinforced concrete. There are two methods for the conventional electrolytic cell planning:

 

i) Demolition using air pick “dry planning”, like “ant gnawing at a bone”. In this way, the working conditions is poor, labor intensity is high and generate a lot of noise, vibration and dust pollution, which is harmful to health. Plus, there other disadvantages like low work efficiency, high maintenance cost, a lot of downtime so it can’t meet production and environmental requirements.

 

Ii) Use a hydraulic jack to push the carbon block between the cathode steel rods and then lift it out with a crane. In this way, it is easy to bend the steel rod and damage the electrolytic tank. Usually, the lifting capacity of the crane in the workshop is limited. Especially for large electrolytic cells, the effect is poor and unsafe, and it is easy to cause an accident.

 

The drawbacks of the traditional planning method are obvious. Chinalco Qinghai Branch and some other large and medium-sized electrolytic aluminum factories in China have introduced and adopted the new technology of hydraulic splitter, which can split and fracture large blocks. The removal of the cathode carbon block and the furnace lining has a remarkable effect and high efficiency, which can shorten the electrolysis cell overhaul period by one third. At the same time, it is easy to operate, simple, safe and environmentally friendly, which can greatly reduce the cost of the trough and the labor intensity of the workers, and improve working environment.

 

2. Operation principle and technical performance of hydraulic splitter

2.1 Operation principle

Conventional mechanical crushing methods, such as air picks, breakers, etc., are used to destroy the structure of an object by the action of external forces. However, some brittle objects that usually need to be broken have high compressive strength, and relatively speaking, their tensile strength is quite low. For example, the sintered cathode carbon block and the lining have the same compressive strength as granite, up to 60-250 MPa, and the tensile strength is usually only 3-10 MPa, that is, the tensile

 

strength is much lower than its compressive strength. The splitter is developed using the low tensile strength of brittle materials, the mechanics and hydraulic mechanism of the wedge group:

First, drill holes of specific diameter and depth on the object to be split, and insert the wedge set of the splitter into the drilled hole. The hydraulic power station generates high-pressure hydraulic oil, which is driven by the hydraulic cylinder on the splitter. The intermediate wedges in the wedge group are driven forward and the two reverse wedges are propped open on both sides. This produces a large splitting force that will destroy the internal structure of the split object and be cleaved within a few seconds. The object will have a crack of 10 - 40 mm and will be split.

2.2 The composition of the hydraulic splitter

A hydraulic splitter usually consists of three parts: hydraulic power station, hydraulic splitter and high- and low-pressure hydraulic pipe.

Hydraulic power station

The hydraulic power station is mainly composed of a power source (electric motor, internal combustion engine, air motor, etc.), a hydraulic pump, a pressure limiting valve, a hydraulic oil tank, etc. The power source generates power and drives the hydraulic pump to provide the splitter high-pressure, low-flow hydraulic oil through the pipes. At the same time, for work safety, the hydraulic system is controlled by a pressure limiting valve with a pressure limit of 60Mpa.

There are two types of hydraulic power stations: portable and mobile. Depending on the power of the hydraulic pump, a hydraulic power station can drive up to ten splitting guns at the same time.

The hydraulic splitter is mainly composed of control valve, hydraulic cylinder and wedge group (including an intermediate wedge and two pairs of reverse wedges). The hydraulic cylinder is made of high quality imported stainless steel, light weight and extremely durable. The surface of the wedge is coated with a special layer of hard alloy, which has high compressive strength and wear resistance, which can increase its service life by more than 10 times.

High- and low-pressure hydraulic pipe and quick connector

High- and low-pressure pipes are used to connect the splitter and the hydraulic power station. The distributor can connect multiple splitting guns with a hydraulic power system. The quick connector can easily connect the whole system in a few seconds. and started working or opened for transportation.

 

2.3 Typical configuration:

The typical configurations of the hydraulic splitter system are as follows: Configuration 1: 1 electro-hydraulic power station, 2 splitting guns, high- and low-pressure hydraulic pipes, and corresponding quick joints, enlarging pads, special grease, etc.

Configuration 2: 1 electro-hydraulic power station, 3 splitting guns, high and low pressure hydraulic pipes, and corresponding quick joints, enlarged pads, special grease, etc.