In GRINDING operation, cutting fluid is utilized for lubrication, cooling, chip removal from contact zone and also cleaning of GRINDING wheel. Despite these advantages, GRINDING fluids make many economic and environmental issues. On the other hand, dry GRINDING generally leading to thermal damages and reduction of surface quality level. Minimum Quantity Lubrication (MQL) technique is a new approach to elimination or reduction of cutting fluids that improves GRINDING performance by efficient penetration to the cutting zone. In this paper, in order to investigate the effect of MQL on GRINDING of steels, raw and hardened High Speed Steel has been selected. GRINDING performance such as tangential GRINDING FORCE, friction coefficient, roughness and morphology of the ground surface and chip form in three states of dry, conventional fluid and MQL have been studied and compared. The results show that MQL technique in comparison with the others lead to improvement of surface quality and also reduction of tangential GRINDING FORCE and friction coefficient in hardened steel, but in the case of raw steel despite of reduction of tangential GRINDING FORCE and friction coefficient, the surface quality is worst.

Coal is known as one of the most important energy sources in different industries. Coal processing has some identified steps like the other ores. One of these steps is comminution which is one of the most significant steps in mineral processing with wide applications in other engineering branches. One of the important subjects in comminution is known as application of GRINDING aids to optimize GRINDING parameters. GRINDING aids or chemicals provide different effects on GRINDING product characteristics. In this work the effect of GRINDING aids such as Alchohol, Terpantinic Acid, Water, Soda and RGA on particle size distribution, consumption energy and selective GRINDING of Geliran coal ore samples were studied Results indicated that GRINDING parameters like size distribution, ash percent and work indices varied with the presence of GRINDING aids. An optimum percent of each GRINDING aids was determined on the basis of laboratory tests results. Consequently Terpantinic acid as the best GRINDING aid in this work reduced the consumption energy and ash percent in finer particle size. Alchohol increased the ash percent of coal in finer particle size and NaOH increased consumption energy and reducing ash percent in the same time. Fresh water did not provide considerable optimization on dry GRINDING process and made some disadvantages. Finally RGA as an industrial cement GRINDING aids provided some advantages and disadvantages and the selection of the best GRINDING aids related .with the strategy of GRINDING process design.

With the high demand of the market change, special CNC machine tools have to support fabrication of low volume production. These types of machine tools need special CAD/CAM systems in order to automatically generate NC program for the new components. In this research, a tool shape oriented feature based CAD/CAM system has been developed for a profile GRINDING machine with a dressing part. A new algorithm is implemented for automatic tool selection, suitable tools layout, and NC program generation. The implemented algorithms have been developed as a prototype software system using Object ARX and Visual C++ operation on the AutoCAD platform.

GRINDING is one of the final processes on the ground part that improves surface quality. GRINDING wheel must be sharpened before surface quality damaged. Dressing parameters must be well adjusted in order to achieve the best conditions of GRINDING wheel surface. In the present research an experimental study has been performed to analyze effect of dressing parameters on surface quality of chrome-molybdenum rolls. Firstly, dressing was performed on GRINDING wheel and topography of wheel, wheel surface quality and surface quality of ground part were compared before and after GRINDING process. Further, a parameters study was carried out to determine the effects of dressing speed, feed rate and dressing depth on the surface roughness of the ground part. Here, 20 experiments were designed by use of central composite design and response surface methodology to determine effects of parameters on the final surface roughness and also identify optimal parameters. In the parameters study obtained results indicated that in minimum dressing feed rate and in minimum dressing depth and in maximum dressing speed are the most effective parameters among process parameters. Finally, the desirability approach function has been used to optimize surface roughness simultaneously.

the changes of BET surface area of a mineral substance during intensive GRINDING process. Validity of the proposed model was tested by the experiments performed using a natural chalcopyrite mineral as well as the published data. It was shown that the model can predict the experimental results with a very good accuracy and can be used to predict what may happen under the similar experimental conditions.Based on experimental observations, a model has been developed to describe the effect of GRINDING time on.

The purpose of this work was to calculate temperature of GRINDING surface of workpiece during creep feed GRINDING using temperature histories and Inverse heat conduction and to predict surface temperature using Fuzzy Logic. Because of inaccessibility of cutting zone and pouring of cutting fluid, there is no possibility to measure temperature of GRINDING surface experimentally. So temperature of GRINDING surface should be estimated using temperature measuring of a point below GRINDING surface in distinct time-steps, taking advantages of special analytical methods and putting them together with heat conduction subjects. In this research temeperatures of three points of workpieces made of cobalt based superalloy was measured using three thermocouples which were located 2mm below GRINDING surface. Then the temperature of GRINDING surface was calculated making use of Inverse heat conduction and experimentaly recorded temperature histories. Afterwards a model was developed to predict temperature of GRINDING surface utilizing experimental data and Fuzzy Logic. Comparison of results showed that suggested model were capable of predicting temperature of GRINDING surface within an average error of about 3%.

Nowadays steel balls wear is a major problem in mineral processing industries and forms a significant part of the GRINDING cost. Different factors are effective on balls wear. It is needed to find models which are capable to estimate wear rate from these factors. In this paper a back propagation neural network (BPNN) and multiple linear regression (MLR) method have been used to predict wear rate of steel balls using some significant parameters including, pH, solid content, throughout of GRINDING circuit, speed of mill, charge weight of balls and GRINDING time. The comparison between the predicted wear rates and the measured data resulted in the correlation coefficients (R), 0.977 and 0.955 for training and test data using BPNN model. However, the R values were 0.936 and 0.969 for training and test data by MLR method. In addition, the average absolute percent relative error (AAPE) obtained 2.79 and 4.18 for train and test data in BPNN model, respectively. Finally, Analysis of the predictions shows that the BPNN and MLR methods could be used with good engineering accuracy to directly predict the wear rate of steel balls.

Mineral processing could be divided into Combination and Concentration. Comminution is one of the most significant steps in mineral processing which has found wide applications in other engineering fields. GRINDING aids/chemicals are used in GRINDING circuits to change the ores breakage characteristics. Size analysis methods have important role and application in mineral processing. There are some size distribution functions to estimate size distribution such as Rosin - Ramler. In this study, the effect of GRINDING aids such as Sodium Tri Poly Phosphate (STPP) and (NaOH) on Sarcheshmeh copper ore and Galiran coal ore samples, were carried out by using Rosin - Ramler function. The effect of STPP and NaOH on breakage parameters of Sarcheshmeh copper and Galiran coal samples had been analyzed using Rosin - Ramler function.The results have shown that there was a considerable correlation between breakage parameters and Rosin- Ramler function. The changes of Rosin - Ramler function coefficients can be used as a good criteria and guideline to analyze the effect of GRINDING aids on breakage parameters such as grind ability, mill production and fineness mean size.