This paper outlines the conceptual and numerical design process of a COMMINUTION equipment centered on particle breakdown through impact. The process is divided into four stages, starting with the generation of device concepts achieved by developing a needs matrix for an optimal machine. Subsequently, in the second stage, various equipment shape proposals were introduced and tested, with the selection of an optimal proposal determined through performance comparisons. For comparison purposes, simulations utilizing the discrete element method (DEM) were conducted, considering analyses of accumulated power from collisions and particle breakage. Once the optimized prototype was identified, a breakage simulation was conducted to measure the device's reduction ratio. In the third stage, the machine elements of the device were calculated. Finally, in the fourth stage, a series of simulations utilizing the finite element method (FEM) were carried out to perform structural and modal analyses of the final design. The evaluated variables identified in the simulations played a crucial role in optimizing the design, ultimately resulting in a device with a reduction ratio of 1: 19. 8 for limestone.

Effect of feeding rate of crushing product was investigated on product particles size distribution by fractal dimension. particle size distribution was calculated according to the cumulative weight of the particles relative to particles size. A comparison between results obtained by Rosin-Rammler distribution and ones obtained by fractal geometry was made by root mean square error (RMSE). COMMINUTION of ore was performed by three jaw, cone and roll crushers, each fed by rates of 0. 5, 1, 1. 5, 2, 3, 4 and 4. 5 kilogram per minute. Fractal dimension of products for jaw, cone and roll crushers were (from 2. 18 to 2. 32), (from 2. 12 to 2. 27), and (from 2. 30 to 2. 43) respectively. Smallness of fractal dimension by cone crusher is due to particles uniformity. Bigness of fractal dimension of roll crusher is due to limited range of particles granulation. Limitation range of particle granulation causes uniformity of product weight distribution. A 2 mm opening sieve was selected as a passing target sieve. Results show that by increasing feeding rate, amount of material passing through of target sieve is decreased. The RMSE obtained by fractal geometry for jaw, cone and roll crushers were (between 8. 01 to 8. 60), (between 3. 50 to 4. 17) and (between 0. 83 to 2. 62) respectively. These ones obtained by Rosin-Rammler distribution were (between 8. 11 to 8. 60), (between 4. 50 to 4. 93) and (between 3. 91 to 7. 91) respectively. A comparison of results obtained by these two methods reveals that fractal geometry is a better way to particle size distributions description.

The present paper deals with the development of process flowsheet for recovery of high-grade graphite from rougher graphite concentrate for use in industrial applications. In the present investigation, since the coarser graphite flakes have a higher demand, an attempt is made at every stage of COMMINUTION, and flash flotation experiments have been carried out, and the end product obtained by stage COMMINUTION followed by flotation has been further subjected to alkali pressure leaching followed by grinding and flotation to recover industrial grade graphite concentrate. During this stage grinding, an additive, a depressant that is being used for depression of silica during flotation, has been used as grinding aid. The data indicates that at any given time of grind, the effect of grinding aid is significantly better as far as the separation efficiency of graphite. Hence, it is concluded that excessive size reduction of graphite is minimised while using a grinding aid. Based on these observations, further studies have been planned for flash flotation using a COMMINUTION circuit with grinding aids. The results of the present study reveals that number of cleaning of rougher concentrate alone will not fetch more than 75% of fixed carbon (FC) with less than 8% yield and 41% recovery. The effect of four stage cleanings continued with starvation dosage in grinding circuit followed by flash flotation indicate that the end product achieved contains 97.8% FC with 11.6% yield and 78% recovery and the overall values loss in tailings contain 3.6% FC. The end product achieved by alkali digestion method from a flotation product [97.8% FC] contains 99.2% FC with overall 10.4% yield and 71% recovery. The process adopted in the present investigation is friendly environment and process flowsheet is an innovative. The end product obtained from this process is useful for various industrial applications. 

The mill shell liner type, rotation speed and the amount of its loading are the key factors influencing the charging behavior, consequently the COMMINUTION mechanism. In this paper, the milling operation of industrial ball mills using the Discrete Element Method (DEM) is investigated. First, an industrial scale ball mill with a Smooth liner type is simulated. Then, by changing liner type, i. e. Wave, Rib, Ship-lap, Lorain, Osborn, and Step liners, six other independent simulations are performed. Effects of mill shell liner type on charge shoulder, toe, impact, and head points, also on head height and impact zone length as well as on the creation of cascading, cataracting, and centrifuging motions for balls at two different mill speeds, i. e. 70% and 80% of its critical speed (NC) are evaluated. Also, in order to validate simulation results, a laboratory-scale mill is simulated. The results indicate that the charge heads are respectively about 240. 13, 283. 40, 306. 47, 278. 12, 274. 42, 274. 42, and 278. 12 cm at the simulations performed with Smooth, Wave, Rib, Ship-lap, Lorain, Osborn, and Step liners at 70% of NC. The corresponding values at 80% of NC are as follows: 256. 08, 264. 56, 313. 54, 298. 45, 313. 54, 311. 60, and 283. 40 cm. On the other hand, the impact zone lengths are respectively about 33. 14, 22. 11, 38. 63, 35. 86, 38. 63, 38. 63, and 49. 59 cm at the simulations performed with the above-mentioned liners at 70% of NC. The corresponding values for impact zone lengths at 80% of NC are as follows: 35. 86, 27. 63, 49. 59, 38. 63, 33. 14, 52. 32, and 41. 38 cm. Comparison of the simulations related to the laboratory scale mill with experimental results demonstrates a good agreement that validates the DEM simulations and the software used.

Objective: To evaluate the clinical and radiographic findings of long head biceps tendon (LHBT) transfer in traumatic proximal humeral fractures with the biceps groove breakage or COMMINUTION. Methods: In this interventional study, subjects surveyed in terms of shoulder function, clinical signs of LHBT tendinitis, radiographic signs of transferred biceps as a possible depressor of the shoulder, and mechanical changes of the scapula. Data were analyzed in SPSS version 21. Results: Fifteen patients were included in the case group (tendon transfer to the conjoined tendon), and 10 patients were evaluated in the control group (non-transfer or non-manipulation of the exposed tendon in the fracture callus of biceps groove). The mean age of the study population was 46. 56±, 14. 31 years, and the majority of patients (14. 56%) were men. The differences between two groups were not significant in terms of the American Society of Shoulder and Elbow Surgeons (ASES) score, University of California at Los Angeles (UCLA) score, and constant shoulder score (CSS) (p=0. 535, p=0. 419, and p=0. 266, respectively). Also, there was no significant differences between the case and control groups regarding the biceps muscle involvement (Popeye sign: p=1. 00,tenderness: p=0. 477,pain: p=1. 00,speed test: p=1. 00,Yergason’, s test: p=1. 00). Conclusion: LHBT transfer to the conjoined tendon in proximal humerus fractures with cleavage or COMMINUTION at the bicipital groove showed no advantages.

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.