High pressure compressed air drill rods and damping adapters for surface mining

Machine-Building Holding JSC (hereinafter referred to as MH JSC) is the only manufacturer in
the Russian Federation that produces all elements of drilling strings for pneumatic impact
drilling under high pressure compressed air. The main elements of drill strings for pneumatic
impact drilling are damping adapters; top adapters; drill rods; centering bushings; bottom
adapters; hammers; drill bits.
MH JSC specialists have extensive experience in production and implementation of drilling
tools, and are constantly working to modify designs and expand the range of products. Over the
past three years, the product line of drill rods for surface mining and damping adapters has
been significantly extended.
All the products have passed pilot tests and are put into series production. To master the serial
production, the necessary metal-cutting, welding, heat treatment equipment, as well as special
ultrasonic testing devices for the metal science laboratory were purchased and put into
operation.
These products are successfully used at many mining enterprises in the Russian Federation, the
CIS and in the countries of the African continent.
Drill rods are used to transmit sufficient torque and load to the drill bit (cone bit) in order to
establish the optimal rate of penetration without compromising the service life of rock
destruction tools (hereinafter referred to as RDT).
Using rigid and straight alloy steel pipes is one of the best ways to eliminate drill string sagging
and borehole deviation. During the production of boreholes, the drill rod is subjected to intense
abrasive wear due to the sandblasting effect created by the rapid rise of drill cuttings and slurry
through the annular space and significant alternating axial loads. Thus, in the production of drill
rods, it is important to use pipes and threaded elements (nipples, couplings) made from quality
high-alloy steel grades, and the production shall be carried out in compliance with all
technological conditions, especially thermal and chemical-thermal operations.
Correctly selected and high-quality drill rods primarily have a positive effect on:
— reduction of the drilling rig wear,
— transfer of energy from the rotator to the RDT,
— RDT centering in a borehole,
— RDT life extension,
— reduction of friction when the string passes through the drill table,
— stabilization of borehole walls to prevent their collapse,
— reduction of drilling costs,
— drilling precision for more efficient drilling and blasting operations,
— improving the final fragmentation of blasted rock.
It is recommended to install a damping adapter on the very top of the drill string, between the
rotator and the drill rod. The damping adapter is a pneumatic mechanism designed to dampen
vibration loads and connect the drill string to the rotator of the drilling rig.
The advantages of using a damping adapter are as follows:
— better monitoring of the torque,
— absorption of harmful vibrations,
— drilling speed increase,
— prolonged service life of drilling rig elements,
— increasing RDT service life.
While introducing these products into series production and receiving feedback from
consumers at all stages of pilot testing, information was obtained and analyzed, which made it possible to significantly improve the product performance. The MH JSC specialists carried out
research work with further implementation of a number of progressive solutions to increase
the durability of drill rods and damping adapters.
Currently, metallurgical companies in the Russian Federation have a wide range of materials to
produce parts for mining engineering, but the correct selection of steels for manufacture of drill
rods and damping adapters plays a significant role in further performance characteristics. The
materials for these products shall withstand the influence of abrasive wear and have sufficient
viscosity. MH JSC, together with Russian metallurgical companies, conducts research work to
improve the physical and mechanical properties of the steels used. It also conducts
experiments to create new special grades of steel that have no analogues in the Russian
Federation and abroad.
MH JSC designers and technologists declare increased requirements for the strength and wear
resistance of manufactured products. The achieved requirements became possible thanks to
modern equipment for thermal and chemical-thermal processing of metals. The Company's
scientific and production staff select the necessary technological modes of heat treatment.
Optimal heating and cooling modes are established thanks to our own modern laboratory
engaged into study and research of the structure and properties of materials.
MH JSC pays special attention to ensuring high quality products, establishing control at all
stages of the production process, starting with quality control of the raw materials used, and
ending with determining the compliance of the released duct with design documentation. The
use of the updated fleet of high-precision metal processing machine tools significantly
increased the requirements for the parts manufacture, which in turn affects much the
performance criteria of the products released. Checking the quality of parts at all stages of
production has become a major part of the production process at MH JSC.
As a result of the modern development of engineering knowledge of personnel and new
production technologies at MH JSC, the quality of drill rods and damping adapters is at a fairly
high level, not inferior to the world's leading analogues, which is successfully confirmed by their
application at many mining enterprises in Russia and abroad.
The MH JSC specialists take a responsible approach to pilot testing of drill rods and damping
adapters. Thanks to accumulated invaluable experience and correct comparability of the
information received, the production process is accelerated, which in turn is a kind of progress
engine for further development of MH JSC in the field of creating reliable and high-performance
drill rods and damping adapters.
Having all the drilling string elements at hand, MH JSC specialists can offer mining enterprises a
unique opportunity for cooperation — concluding a meter-by-meter contract, in which the
client pays only for the actual linear meters drilled. Our specialists also offer optimal conditions
for service and warranty maintenance of the entire range of used drilling tools produced by MH
JSC.