scholarly journals Performance and Reuse of Steel Shot in Abrasive Waterjet Cutting of Granite

2021 ◽  
Author(s):  
Yohan Cha ◽  
Tae-Min Oh ◽  
Gun-Wook Joo ◽  
Gye-Chun Cho
Keyword(s):  
Particle Size ◽  
Industrial Waste ◽  
High Hardness ◽  
Rock Cutting ◽  
Cutting Performance ◽  
Abrasive Waterjet ◽  
Steel Shot ◽  
Abrasive Surface ◽  
The Cost ◽  
Recycled Steel

AbstractSteel shots are suitable for abrasive waterjet rock cutting and recycling because of the high hardness and magnetic properties of steel. This study evaluated the rock-cutting performance and recycling characteristics of steel shot waterjet. The rock-cutting responses of steel shot and garnet were compared at the same waterjet conditions. The used steel shot was collected and the particle-size changes were evaluated before reuse, and its cutting performance was re-evaluated. Overall, the steel shot waterjet yielded improvements in performance in the range of 30–50% compared with the garnet waterjet. Moreover, the recycled steel shot yielded a 50% reduction in cutting performance. Rust was observed on the surface of the used steel shot, the used steel shots were partially destroyed, and the debris on the abrasive surface needed to be removed by drying. The reusable steel shot left on the 80th sieve converged to 60% in each recycling run. The results of this study can be used to reduce the cost of abrasive waterjet and industrial waste.

scholarly journals Effect of Garnet Characteristics on Abrasive Waterjet Cutting of Hard Granite Rock

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Tae-Min Oh ◽  
Gun-Wook Joo ◽  
Yohan Cha ◽  
Gye-Chun Cho
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Rock Cutting ◽  
Cutting Performance ◽  
Abrasive Waterjet ◽  
Test Results ◽  
Abrasive Particles ◽  
Waterjet Cutting ◽  
Abrasive Waterjet Cutting

Abrasive waterjet cutting technology has come back into use in the field of rock excavation (such as for tunneling) due to the need for precision construction with low vibration. Because the abrasive particles play an important role in efficient erosion during the cutting process, the abrasive characteristics strongly affect the rock cutting performance. In this study, rock cutting tests were performed with five different coarse (40 mesh) garnets to explore the effect of the abrasive feed rate, physical properties, and particle size distribution on rock cutting performance. In addition, garnet particle disintegration was investigated with garnet characteristics for the abrasive waterjet. The test results indicate that the particle size distribution, garnet purity, specific gravity, and hardness are the most important parameters for rock cutting performance. This study offers better understanding of coarse garnet performance and efficiency according to the garnet characteristics. This should provide assistance in selection of the garnet needed to achieve the desired performance for hard rock cutting.

Effect of Abrasive Feed Rate on Rock Cutting Performance of Abrasive Waterjet

2019 ◽  
Vol 52 (9) ◽  
pp. 3431-3442 ◽  
Author(s):  
Tae-Min Oh ◽  
Gun-Wook Joo ◽  
Gye-Chun Cho
Keyword(s):  
Feed Rate ◽  
Rock Cutting ◽  
Cutting Performance ◽  
Abrasive Waterjet

scholarly journals Effects of Focus Geometry on the Hard Rock-Cutting Performance of an Abrasive Waterjet

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Yohan Cha ◽  
Tae-Min Oh ◽  
Gye-Chun Cho
Keyword(s):  
Momentum Transfer ◽  
Hard Rock ◽  
Empirical Relationship ◽  
Abrasive Particle ◽  
Rock Cutting ◽  
Maximum Energy ◽  
Cutting Performance ◽  
Granitic Rocks ◽  
Abrasive Waterjet ◽  
Cutting Depth

Abrasive waterjets are being increasingly used in civil engineering for rock and concrete cutting, particularly for the demolition or repair of old structures. The energy of an abrasive waterjet is primarily provided by the accelerated abrasive. The momentum transfer during mixing and acceleration determines the abrasive velocity, which affects the cutting performance. Meanwhile, the geometry of the focus at which mixing occurs influences the momentum transfer efficiency. In this study, the effects of the focus geometry on the optimum abrasive flow rate (AFR) and momentum transfer characteristics in hard rock cutting were investigated. Experiments were conducted using granite specimens to test the AFR under different focus geometry conditions such as diameter and length. The results show that the focus geometry significantly affects the maximum cutting depth and optimum AFR. The maximum cutting energy was analyzed based on the cutting efficiency of a single abrasive particle. In addition, the momentum transfer parameter (MTP) was evaluated from the empirical relationship between the maximum energy and the cutting depth for granitic rocks. Accordingly, a model for estimating the MTP based on the AFR was developed. It is expected that the results of this study can be employed for the optimization of waterjet rock cutting.

scholarly journals Simple Approach for Evaluation of Abrasive Mixing Efficiency for Abrasive Waterjet Rock Cutting

2021 ◽  
Vol 11 (4) ◽  
pp. 1543
Author(s):  
Yohan Cha ◽  
Tae-Min Oh ◽  
Hyun-Joong Hwang ◽  
Gye-Chun Cho
Keyword(s):  
Flow Rate ◽  
Particle Density ◽  
Empirical Relationship ◽  
Cost Effective ◽  
Rock Cutting ◽  
Cutting Performance ◽  
Abrasive Waterjet ◽  
Mixing Efficiency ◽  
Abrasive Waterjets ◽  
Design Selection

The abrasive mixing variables, such as the abrasive and water flow rates and the focus geometry parameters, determine the profitability of an abrasive waterjet system. In this study, the mixing efficiency characteristics in abrasive waterjet rock cutting were investigated. To demonstrate comprehensively the efficiency reduction due to collision during abrasive mixing, the chance of collision was expressed as the distance between the abrasive particles in the focus. The mixing efficiency was then assessed by utilizing the empirical relationship between the experimental results and the developed model. Based on the particle density and the velocity, the closer particles showed higher chances of collision, thus yielding a reduced cutting performance. Using the distance between particles model, the optimum abrasive flow rate and the cutting performance of abrasive waterjet systems can be estimated. This developed model can be used for the design selection of abrasive flow rate and systems for the cost-effective use of abrasive waterjets.

A Study on Recycling of Supreme Garnet in Abrasive Waterjet Machining

2012 ◽  
Vol 248 ◽  
pp. 499-503 ◽  
Author(s):  
Vu Ngoc Pi ◽  
Hoang Van Chau ◽  
Tran Quoc Hung
Keyword(s):  
Particle Size ◽  
Cutting Performance ◽  
Abrasive Waterjet ◽  
Abrasive Waterjet Machining ◽  
Waterjet Machining ◽  
The Way

This paper presents a new study on the recycling of Supreme garnet (or IMC garnet) in abrasive waterjet machining. In this study, the reusability of the garnet was investigated. Also, the optimal particle size for the recycling of the garnet was pointed out. In addition, the cutting performance and the cutting quality of the recycled abrasive were investigated by comparing with that of new abrasives. From the results, the way how to recycle effectively the garnet was proposed.

scholarly journals Feasibility of fly ash as fluxing agent in mid- and low-grade phosphate rock carbothermal reduction and its reaction kinetics

2021 ◽  
Vol 10 (1) ◽  
pp. 157-168
Author(s):  
Biwei Luo ◽  
Pengfei Li ◽  
Yan Li ◽  
Jun Ji ◽  
Dongsheng He ◽  
...  
Keyword(s):  
Particle Size ◽  
Fly Ash ◽  
Reaction Time ◽  
Carbothermal Reduction ◽  
Industrial Waste ◽  
Phosphate Rock ◽  
Molar Ratio ◽  
Low Grade ◽  
Carbon Excess ◽  
Fluxing Agent

Abstract The feasibility of industrial waste fly ash as an alternative fluxing agent for silica in carbothermal reduction of medium-low-grade phosphate ore was studied in this paper. With a series of single-factor experiments, the reduction rate of phosphate rock under different reaction temperature, reaction time, particle size, carbon excess coefficient, and silicon–calcium molar ratio was investigated with silica and fly ash as fluxing agents. Higher reduction rates were obtained with fly ash fluxing instead of silica. The optimal conditions were derived as: reaction temperature 1,300°C, reaction time 75 min, particle size 48–75 µm, carbon excess coefficient 1.2, and silicon–calcium molar ratio 1.2. The optimized process condition was verified with other two different phosphate rocks and it was proved universally. The apparent kinetics analyses demonstrated that the activation energy of fly ash fluxing is reduced by 31.57 kJ/mol as compared with that of silica. The mechanism of better fluxing effect by fly ash may be ascribed to the fact that the products formed within fly ash increase the amount of liquid phase in the reaction system and promote reduction reaction. Preliminary feasibility about the recycling of industrial waste fly ash in thermal phosphoric acid industry was elucidated in the paper.

Factors Influencing the Particle Size Distribution in an Abrasive Waterjet

1991 ◽  
Vol 113 (4) ◽  
pp. 402-411 ◽  
Author(s):  
T. J. Labus ◽  
K. F. Neusen ◽  
D. G. Alberts ◽  
T. J. Gores
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Cutting Speed ◽  
Target Material ◽  
Abrasive Waterjet ◽  
Sieve Analysis ◽  
Size Distributions ◽  
Mixing Process ◽  
Jet Mixing

A basic investigation of the factors which influence the abrasive jet mixing process was conducted. Particle size analysis was performed on abrasive samples for the “as-received” condition, at the exit of the mixing tube, and after cutting a target material. Grit size distributions were obtained through sieve analysis for both water and air collectors. Two different mixing chamber geometries were evaluated, as well as the effects of pressure, abrasive feed rate, cutting speed, and target material properties on particle size distributions. An analysis of the particle size distribution shows that the main particle breakdown is from 180 microns directly to 63 microns or less, for a nominal 80 grit garnet. This selective breakdown occurs during the cutting process, but not during the mixing process.

scholarly journals Numerical Simulation of Rock Plate Cutting with Three Sides Fixed and One Side Free

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
Zhenguo Lu ◽  
Lirong Wan ◽  
Qingliang Zeng ◽  
Xin Zhang ◽  
Kuidong Gao
Keyword(s):  
Numerical Simulation ◽  
Cutting Force ◽  
Cutting Speed ◽  
Rock Cutting ◽  
Numerical Results ◽  
Peak Force ◽  
Cutting Performance ◽  
Conical Pick ◽  
Cutting Method ◽  
Cutting Angle

In order to overcome conical pick wear in the traditional rock cutting method, a new cutting method was proposed on account of increasing free surface of the rock. The mechanical model of rock plate bending under concentrated force was established, and the first fracture position was given. The comparison between experimental and numerical results indicated that the numerical method is effective. A computer code LS-DYNA (3D) was employed to study the cutting performance of a conical pick. To study the rock size influenced on the cutting performance, the numerical simulations with different thickness, width, and height of a rock plate was carried out. The numerical simulation with the different cutting parameters of cutting speed, cutting angle, and cutting position influenced on cutting performance was also carried out. The numerical results indicated that the peak force increased with the increasing thickness of rock plate. With the increasing width and height of the rock plate, the peak force decreased and then became stable. Besides, the peak force decreased with the increasing of cutting position lxp/lx. Moreover, the peak force increased and then decreased with the increasing of cutting angle. The cutting speed has nonsignificant influence on the peak force. The strong exponential relationship was obtained between the peak force and cutting position, thickness, height, and width of the rock plate at a confidence level of 0.95. A binomial relationship was observed between the peak force and cutting angel. The cutting force comparison between traditional rock cutting and rock plate cutting indicated that the new cutting method can effectively reduce peak cutting force.

scholarly journals Influence of Traverse Velocity and Pump Pressure on the Efficiency of Abrasive Waterjet for Rock Cutting

2017 ◽  
Vol 40 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Paola Bruno Arab ◽  
Tarcísio Barreto Celestino
Keyword(s):  
Rock Cutting ◽  
Abrasive Waterjet ◽  
Pump Pressure

Machining Capabilities of Abrasive Waterjet on Stainless Steel 304

2019 ◽  
Vol 895 ◽  
pp. 313-318
Author(s):  
S.B. Supriya ◽  
S. Srinivas
Keyword(s):  
Stainless Steel ◽  
Stainless Steels ◽  
Cutting Tool ◽  
High Hardness ◽  
Abrasive Waterjet ◽  
Depth Of Cut ◽  
Machined Surface ◽  
Sem Images ◽  
Enhanced Production ◽  
Work Material

Stainless Steels are possessing fabrication flexibility, high hardness, durability, low maintenance, high strength and resistance to heat and corrosion. This alloy steel is extensively used in various engineering applications. Some of the conventional machining techniques results in loss of original properties of stainless steel work material and makes it to behave like ordinary material within the machined surface. Machining of Stainless steels is more challenging due to its high alloying content. Problems such as application of huge coolant supply and poor chip breaking while machining, work hardening in work material, use of cutting tools with varying tool signature, results in enhanced production cost and time. Further, it is important to ensure that there is no machine tool-cutting tool vibration leading to edge chipping of cutting tool. To avoid all these problems, Abrasive water jet machining (AWJM) is used. This paper presents the machining capabilities of AWJ on Stainless Steel304. Influence of dynamic input parameters such as jet pressure, speed of traverse and abrasive flow rate on the depth of cut is investigated. An empirical model is proposed for depth of cut and an error analysis is done with measured and modeled values of depth of cut. It was found that traverse speed influences more than other parameters. SEM images indicated smooth surface at entrance and waviness at exit side. The model proposed predicts the depth of cut more or less accurately.

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