With the continuous expansion of the scale of mining projects and the development of mining machinery manufacturing industry, hydraulic rock drill jumbos have gradually become the main equipment for mechanized rock drilling. As a high-efficiency rock drilling machine, the hydraulic rock drill jumbo has standard requirements on the type, specification, structure, and quality of the matching rock drilling tools. What are these requirements?

Requirements of hydraulic rock drill jumbos for rock drilling tools are high-quality rock drilling tools, optimum drilling rate, and minimum hole deflection.

1. Quality of rock drilling tools

In foreign projects, the calculation of working hour costs is given great importance in the whole project because of the high labor compensation. For example, the production of hydraulic rock drill jumbos usually allocates the cost of equipment, production system cost, and per capita compensation required for each working hour by year. The average working hour cost of a drill jumbo in Sweden amounts to 380~450 USD/hour. Therefore, the loss due to non-productive time is very high.

In foreign countries, hydraulic rock drill jumbos operate in a single shift, with a single arm drilling about 50,000 meters of gun hole progress per year. Generally, the service life of shank adapter is required to be more than 3000 meters to reduce the time for dismantling and replacing the shank adapter. The requirements for drill rods and rock drill bits are also quite high because a broken drill rod will not only lose rock drill bits but also cause waste holes. At the same time, due to the high degree of automation of hydraulic rock drill jumbo, operators do not need to pay a lot of labor intensity during normal production, while dismantling the machine to replace shank adapter, salvaging the broken drill rod or resharpening rock drill bit not only wastes working hours but also increases the labor intensity of operators. Therefore, when foreign users choose rock drilling tools, they not only pay attention to the price of the product but also pay more attention to the quality of the product.

2. Drilling rate

In the operation of rock drill jumbos, except for labor compensation and purchase cost of rock drilling tools, other working hours costs are regarded as fixed costs, and the cost of rock drilling tools accounts for a very low proportion of the total cost in rock drilling operations. Therefore, increasing the speed of rock drilling means reducing the construction cost, so foreign users attach great importance to the selection of different types of rock drilling tools and increasing the speed of rock drilling.

3. Blast hole deflection

In medium and deep hole rock drilling and blasting, the deflection of blast holes means less charge and shorter hole spacing, which leads to lower mining volume. Therefore, foreign users have high requirements for the straightness of blast holes, which are usually controlled within a small range of errors. The main reasons for the blast hole deviation are the hole entry error during drilling, the calibration blast hole error, and the straightness error generated during the rock drilling process of rock drilling tools. The first two errors can be eliminated in fully hydraulic rock drill jumbos or computer-controlled hydraulic drill jumbos, while the skewing of the hole caused by the structure of rock drilling tools becomes the main reason. With the deepening of the drilling depth, the skew will be aggravated, which will eventually cause the waste hole. The best way to reduce or eliminate the skew of blast holes is to use guided rock drilling tools.

The requirements of hydraulic rock drill jumbos for rock drilling tools are inseparable from the enterprise’s pursuit of reducing rock mining costs and high production efficiency. Therefore, manufacturers of rock drilling tools must pay attention to the production and development of rock drilling tools for rock drill jumbos to provide a greater range of hydraulic rock drill jumbos.