Figure 2. Basic drilling method selection guide for rock using noncoring methods (Littlejohn and Bruce, 1977. Adapted from McGregor, 1967). Of course there have been many significant developments and modifications in the intervening period, but the basic guidelines remain the same: Rotary drilling is economic in all hole sizes in soft-medium rocks.
Kefid · The following data shown in table are obtained from open cast mine relates to blast hole drilling in coal mines. The purpose of this study was to observe the influence of parameters like weight on bits, rotary speed, specific energy, rock characteristics on penetration rate of a rock roller bit. Table – 2 Rock characteristics: Mica
Kefid · Performance analysis of drilling machines using rock modulus ratio abrasivity index and Shore hardness. The model for hybrid bits indicated that the significant parameters were weight on bit, round per minute grain-shape factor and Mohs hardness. The model for impregnated bits comprised two hardness parameters (Mohs hardness and Shore hardness
Kefid · the top of rock and is useful in solution cavity iden tification in karstic terrain. Types of non-core drilling include air-track drilling, down-the-hole percussive drilli ng, rotary tricone (roller bit) drilling, rotary drag bit drilling, and augering with carbide-tipped bits in …
Author: D. Akbay, R. Altindag
Rock drill operations are classified as top hammer drilling (THD), down-the-hole drilling, or rotary drilling. The rock drill in the THD method consists of a percussion drill rig module and a
Kefid · Drilling method generally employed are hydraulic drifter drilling and DTH drilling. The HD90MKIV and HD110 with suitable attachments is an ideal machine for all types of rock drilling work. A wide variety of hydraulic drifters and rotary heads are available to suit different formations and hole …
Cited by: 2
Kefid · 1. Introduction and General Information This method statement provides the details of the materials, the equipment, the procedure and relevant documents related to the Rock Blasting activity, including the quality control verifications, the measurement verifications, and also the safety precautions to be implemented for this work.
Kefid · 1.8 Hole Inclination when using ”Row Types” This method is used in all cases when full height of the bottom charge is not reached with one Calculation of Specific Drilling and Specific Charge are in the program based on Rock Volume per Blast. In turn the Rock Volume is based on Width of the Blast, which means the distance between
Kefid · development and application of Long Hole drilling as a viable, practical method of narrow reef mining. Appendix I mined using hand-held pneumatic rock drills and scraper for the 64 mm blast hole were 0.43 metres per minute. However, this was increased to 0.75 metres per minute
Kefid · National Institute of Technology Rourkela This is to certify that the thesis entitled “ Optimization of Blasting Parameters in Opencast Mines ” submitted by Sri Manmit Rout (Roll. No.: 10305019) and Sri Chinmay Kumar Parida (Roll. No.: 10305017), in fulfillment of the requirements for the award of Bachelor of
Kefid · The hole is generally filled from 1/3 to 1/2 its depth with the explosive. (iv) The hole is then summed. Stemming consists of filling the remaining 2/3 to 1/2 depth of blast-hole (above the last compacted layer of explosive) with inert and non-combustible material like powdered clay, rock and, sand. This is also done in installments.
Kefid · Today we will explain more on rotary drilling method. Rotary Drilling Fundamentals. Rotary drilling is a versatile method for blast hole drilling. It is the dominant method for holes larger than 203 mm (8”) diameter. In smaller holes, it is most common in softer rock formations.
When it comes to using a blast hole drill, you’re going to need to have the best equipment available on the market.At Gill Rock Drill Company, we are our own supplier and manufacturer, and only provide the best tools and equipment for our customers, which include our blast hole drill.
Kefid · While the relative rock hardness has an effect both on drilling and explosives performance, environmental factors exert their influence as well. Among the factors to consider in studying drilling costs are: bit costs, labor, fuel consumption, penetration rates, maintenance, machine life, and machine cost. For example, severe water
Kefid · Drilling and blasting is the controlled use of explosives and other methods such as gas pressure blasting pyrotechnics, to break rock for excavation. It is practiced most often in mining, quarrying and civil engineering such as dam, tunnel or road construction. The result of rock blasting is often known as a rock cut. Drilling and blasting History · Procedure · Rock support · Gallery · See also · References
Kefid · of density itself. This research investigated a common industry method used to determine the bulk density of rock core samples typically encountered in the mining industry. The main problem in determining the bulk density of rock core is obtaining an accurate estimate of the rock core’s total volume.
The concept of rotary drilling as a method differs entirely from percussive drilling. In the latter, the rock is caused to fail by imparting a sharp blow onto a bit and using a rotation device to merely turn the bit a sufficient amount to keep it indexed to cut a circular path.
Drilling and blasting as a tunnel excavation method. ma king the cut easy to blast. Hole drilling and One of the main hazards in rock tunneling by using the drill and blast method is the
Kefid · Spacing = Hole diameter x 12 Burden = 0.5 x production blast burden (B) Uncharged length at top = 10 x D Powder factor = 0.5kg per square metre of face Do not stem holes. Fire all holes on the same delay, or in groups of ≥ 5 holes Smooth Blasting Spacing = 15 x Hole diameter (hard rock) 20 x Hole diameter (soft rock) Burden = 1.25 x Spacing
Kefid · This drilling method uses a heavy bit that is repeatedly lifted and dropped that crushes and breaks the formation. Figure 6.1 shows the basic elements of a cable tool rotary method; then, the hole is completed using a cable tool rig. Temperatures can be measured at the surface, after water is brought up in the bailer. If the hole is deep
Kefid · “blows” to the rock downhole are delivered by the bit, while a rotational device ensures that the bit impacts a new rock surface with each blow. A feed force is applied to maintain rock/bit contact. Compressed air is used to remove or “flush” the drill cutting from the hole, thereby advancing the hole depth at an efficient rate.
Cited by: 1
General Drilling Method and Application. General Drilling Method and Application. February 6, 2018. The up-down movement of rotary tricon bit also has the each cone contact the rock in turn to break rock continuously. Mining Drilling Rigs and Blast Hole Drill; Water Wells.