Relations between Texture Coefficient and Energy Consumption of Gang Saws in Carbonate Rock Cutting Process

Texture coefficient is one of the most influential parameters in rock engineering specifications in various projects including drilling, cutting, permeability of all-section drilling devices, etc. Meanwhile, investigating and forecasting the energy consumption of saw cutters are one of the most important factors in estimating the cutting costs. The present study aims to investigate the relationship between rock texture characteristics and the amount of energy consumption of the gang saw machine in the process of cutting carbonate rocks. To evaluate the effects of texture on the rocks' engineering specifications, 14 carbonate rock samples were studied. A microscopic thin section was made from each rock specimen. Then, five digital images were taken from each section under a microscope and the values of area, environment, the largest diameter and the smallest diameter of all grains in each image were determined. Using these specifications, the coefficient of texture of all rock samples was calculated and the relationship between the texture coefficient and the rate of energy consumption of the gang saw machine was investigated for the studied samples. The study results indicated that there was a significant relation between the texture coefficient and energy consumption rate in the three groups of carbonate rocks

ASSOCIATION MAPPING OF MORPHOLOGICAL AND PHYSIOLOGICAL TRAITS OF FLAG LEAF RELATED TO DROUGHT TOLERANCE IN BARLEY

Association mapping has proven to be a powerful approach for dissecting the genetic basis of complex traits. In this study, QTLs controlling flag leaf characteristics under drought stress were detected in a set of 148 modern spring barley cultivars using AM analysis. Flag leaf length (FLL), flag leaf width (FLW), relative water content (RWC), chlorophyll content, and maximum quantum efficiency of PSII (Fv/Fm) which are important in photosynthetic rate, were evaluated under normal irrigation and drought stress conditions at grain filling stage. Population structure was estimated using Structure2.3 and linkage disequilibrium (LD) was estimated by the ‘Full Matrix LD’ using Tassel5.0. Significant marker/trait associations were investigated based on K-Q matrix using Tassel3.0. The analysis of population structure divided the cultivars into two sub-groups. Significant LD values (P < 0.01) between polymorphic sites with regions of high and low LD were observed. A total of 84 significant putative genomic regions were identified, which delineated into 37 QTLs under two water treatments. Two stable QTLs on 2H and 3H were detected for FLL in drought stress treatment. A QTL for FLL were detected on 2H in normal treatment, which alone explained around 11% of phenotypic variance of FLL. This QTL was also associated with the expression of FLW and explained around 7.5% of phenotypic variance. The results suggest that major loci are located on chromosomes 2H, 3H, 4H and 5H involved in the development of flag leaf characteristics and could be used as selection criteria in barley breeding for drought tolerance

THE STUDY OF ENERGY CONSUMPTION IN THE DIMENSION STONE CUTTING PROCESS

U industriji arhitektonsko-građevnoga kamena važno je predvidjeti utrošak energije kod njegova rezanja. Utvrđivanje odnosa strojnih varijabli s tim utroškom važan je postupak. Konstruirani su ispitni, laboratorijski rezaći strojevi s mogućnošću promjene radnih varijabli. Prikupljeni rezultati statistički su analizirani usporedbom s potrošnjom energije. Testiranje je načinjeno na sedam uzoraka karbonatnih stijena, uz različite vrijednosti dubine zarezivanja, jakosti i brzine. Tako je dobiven model utroška energije, postavljen u odnosu na svaku promatranu, nezavisnu varijablu. Statistička analiza načinjena je paketom SPSS. U njoj su primijenjeni t-test i F-test. Vrijednosti predviđene takvim modelom prikazane su dijagramom raspršenja. Rezultati su vrlo bliski linearnomu modelu predstavljenomu pravcem pod kutom od 45 stupnjeva. Takav model odlikuje se visokim stupnjem točnosti te korelacije između predviđenih i opaženih vrijednosti. Stoga on može biti korišten za izračun utroška energije uz različite ulazne varijable.In the dimension stone industry, predicting the energy consumption in rock cutting process and examining its relationship with machining parameters are among the most important steps to achieve the optimum conditions in terms of energy consumption. A laboratory scale cutting machine with changing machining parameters was made and its energy consumption was evaluated through the statistical analysis. Tests were carried on seven carbonate rock samples under different operating conditions at different depths of cut, feed rates and peripheral speeds. Finally, an energy consumption model was obtained through statistical studies using SPSS software. The t and F tests were used to validate the model and to control each of the independent variables. To see the prediction capability of the derived model, the scatter diagram of the observed and estimated values was plotted. The results showed that the points are very close to the 1:1 diagonal straight line. It concluded that the developed model has a high degree of accuracy with a high correlation between the predicted and the observed values. Due to its high accuracy, the proposed model can be used in the calculation of energy consumption under various operating parameters

An Elastomer Additive Improving Elastic Properties of Heavy Weight Oil Well Cement: A Laboratory Study

The use of elastomer additives to solve the problems in oil well cementing has been investigated in recent years by several research groups in the petroleum industry. This study includes the laboratory examination of the effect of elastomer additives on the physical properties of heavy-weight oil well cement. In the research process, a candidate well is selected and the properties of the cement slurry used in a problematic section of the well are tested in the laboratory. Then, elastomer additives are added as an elastic agent and the improvements in the cement slurry and stone properties are studied. This article discusses the problems associated with the conventional heavy-weight oil well cement used in the candidate well and reports the detail of the improvements in cement properties obtained by adding an elastomer additive to the cement slurry formulation as an elastic agent. These properties include cement slurry rheological properties, free water, fluid loss, thickening time, cement stone elasticity properties, and compressive strength. The elastomer additive increases the yield point and plastic viscosity, but it decreases the free water and fluid loss of cement slurry. In addition, the cement stone compressive strength decreases; however, there is an optimum concentration of the elastomer additive at which the maximum compressive strength is reached. Moreover, the elasticity properties of the cement stone are improved and a lower value for the Young’s modulus and a higher value for the Poisson’s ratio are achieved. The theories supporting the results are discussed in the discussion section. The results of this study can be used to optimize the cement slurry design in any given set of conditions.</span

Analyzing the effect of ore grade uncertainty in open pit mine planning; A case study of Rezvan iron mine, Iran

Due to uncertain nature of grade in ore deposits, considering uncertainty is inevitable in geological modelling of resources and mine planning. In other words, uncertainty in grade of mineralized materials, is one of the most significant parameters need attention in mine planning. In this paper, a comparative procedure utilizing Sequential Gaussian Simulation (SGS) and traditional Ordinary Kriging (OK) was applied in an iron ore mine, and the influence of ore grade uncertainty in mine planning was investigated. It was observed that grade distribution, resulted from the SGS is almost identical to that of the real exploration data as compared to the OK method. Also it is emphasized that uncertainties including ore grade of deposit would significantly affect the technical and financial aspects of plans. Comparison shows that the simulation-based ultimate pits exhibits less risk in deviating from quantity and quality targets than traditional approach based on a single orebody model obtained by OK method. Using SGS method, there was an increase in the value of net present value of mine plans

Using an Elastic, Expandable Sealant System for Zonal Isolation of Maroon Wells: a Laboratory Study

An oil and gas well cementing in Gachsaran formation, where sustained annular pressure has been reported in many wells, presents a big challenge in Maroon field. The main challenges are preventing gas migration and achieving zonal isolation using a competent cement sealant system which is able to withstand downhole stresses and high temperatures during production cycles. Unlike conventional cement systems, properties, such as, high Poisson’s ratio and low Young’s modulus compared to that of the rock were optimized in the new system to achieve mechanical resistance and durability. The use of elastic-expandable additives to solve problems in oil well cementing has been investigated in recent years by several research groups in the petroleum industry. This study includes the laboratory examination of the effect of an elastic-expandable additive on the physical properties of a new cement sealant system. In the research process, a candidate well was selected and the properties of the used cement slurry in a problematic section of the well were evaluated in the laboratory. Then, the elastic-expandable additive was added as an elastic agent and the improvements in the cement slurry and stone properties were studied. This article discusses the problems associated with the conventional cement used in the candidate well and gives the detail of the improvements in cement properties obtained by adding the elastic-expandable additive to the cement slurry formulation as an elastic agent. The elastic-expandable additive increases the Poisson’s ratio and expansion set cement, but it decreases the Young’s modulus and fluid loss of the cement slurry. In addition, to prevent gas migration and achieve zonal isolation, there is an optimum concentration of the elastic-expandable additive at which the maximum compressive strength is reached. The results of this study can be used to optimize the cement slurry design in any given set of conditions

INVESTIGATING THE ROLE OF COOLANT AND LUBRICANT FLUIDS ON THE PERFORMANCE OF CUTTING DISKS (CASE STUDY: HARD ROCKS)

Pravilan odabir rashladnih i mazivih fluida u rezanju tvrdoga arhitektonsko-građevinskog kamena jedan je od najvažnijih čimbenika uspješnosti toga postupka. Također utječe i na veću ekonomičnost pridobivanja te kvalitetu pridobivenoga kamena. Stoga je prikazano istraživanje uloge spomenutih fluida u postupku pripreme takva kamena. Uporabljeno je 10 uzoraka granita prikupljenih u iranskome kamenolomu. Izmjerena su njihova fizička i mehanička svojstva, uključujući jednoosnu tlačnu čvrstoću, tvrdoću prema Mohsovoj ljestvici, faktor trošenja prema Schimazeku te Youngov modul elastičnosti. Uporabljene su tri vrste rashladnih i mazivih tekućina, od kojih su dvije otopine na bazi sapuna u kojima je omjer maziva i hladiva bio 1 : 40 do 1 : 20. Korištene su dvije vrijednosti kojima se određivao način obradbe kamena – stupanj napredovanja i dubina rezanja. Načinjeno je 160 laboratorijskih testiranja za sve omjere fluida te je pri tome mjerena potrošnja električne energije. Rezultati su procijenjeni statistički i drugim algoritmima te su modelirani algoritmom radijalne bazne funkcije. Temeljem rješenja dobivenih objema analitičkim metodama ocijenjeno je kako omjer maziva i praha za rashlađivanje 1 : 20 ima najpovoljniji utjecaj na količinu potrebne električne energije prilikom obradbe kamena.The correct and proper selection of coolant and lubricant fluids in the dimension hard rocks’ cutting process is one of the most important factors in the improvement of the cutting process, and in the increase of economic efficiency and quality of stone production. Therefore, this present study aims to study the role of coolant and lubricant fluids in the cutting performance of dimension hard rocks. In this study, 10 granite stone samples were collected from Iranian quarries and their physical and mechanical properties including their uniaxial compressive strength, Mohs hardness, Schimazek’s F-abrasiveness factors and Young modulus were measured and determined. According to the three types of coolant and lubricant fluids, including the two types of soap water with ratios of 1 to 40 and 1 to 20 and one type of lubricant and coolant powder, and using two different operational parameters such as feed rate (Fr) and depth of cut (Dc), 160 laboratory tests for each of these fluids were studied and measured in order to determine the maximum electrical current consumed by the machine. The obtained results were statistically and intelligently evaluated and analyzed through the radial basis function (RBF). Based upon the results obtained from both the analytical methods, the lubricant and coolant powder with ratios of 1 to 20 had the maximum and minimum effects on the reduction of the maximum consumed electrical current in the hard rocks’ cutting process

OCJENA REZIVOSTI STIJENA S LANČANOM SJEKAČICOM PRIMJENOM TEHNIKE PROMATHEE

One of the most significant factors in the estimation of dimension stone quarry cost is the production rate of rock cutting machines. Evaluating the production rate of chain-saw machines is a very significant and practical issue. In this research, it has been attempted to evaluate and select the suitable working-face for a quarry by examining the maximum production rate in the Dehbid and Shayan marble quarries. For this purpose, fi eld studies were carried out which included measuring operational characteristics of the chain-saw cutting machine, the production rate and sampling for laboratory tests from seven active case studies. Subsequently, the physical and mechanical properties of rocks including: Uniaxial Compressive Strength (UCS), Brazilian Tensile Strength (BTS), Los Angeles abrasion, quartz content, water absorption percentage, porosity, Schmidt hardness and grain size for all sample measurements were studied after transferring the samples to a rock-mechanics laboratory. Finally, the sawability of the quarried working-faces was evaluated using the PROMETHEE multi-criteria decision-making (MCDM) model according to the physical and mechanical properties. The results of the study indicated that the number 1 and 5 working-faces from the Dehbid and Shayan quarries are the most suitable working-faces in terms of production rate with the maximum recorded production values (4.95 and 3.1 m2 /h), and with net fl ow rates (2.67 and -0.36) respectively.Jedan od najvažnijih čimbenika u procjeni cijene vađenja građevinskoga kamena jest njegov iznos pridobivanja tijekom strojnoga rezanja. Procjena iznosa proizvodnje takvih strojeva ima vrlo veliku i praktičnu ulogu. Ovdje je načinjena procjena i odabir prikladnoga radilišta unutar kamenoloma radi postizanja najvećega iznosa proizvodnje. Za analizu su odabrani kamenolomi mramora Dehbid i Shayan. Načinjena su terenska ispitivanja, tj. mjerenje operativnih svojstava sjekačice, iznosa pridobivanja te uzorkovanje za laboratorij na sedam smjestišta. Zatim su u laboratoriju za mehaniku stijena izmjerena fizička i mehanička svojstva stijena poput jednoosne kompresijske čvrstoće, brazilske vlačne čvrstoće, abrazije metodom Los Angeles, udjela kvarca, postotka apsorpcije vlage, šupljikavosti, Schmidtove čvrstoće i veličine zrna. Na kraju je ocijenjena rezivost materijala na radilištu kamenoloma uporabom tehnike PROMETHEE, koja predstavlja alat za donošenje odluka na temelju više kriterija koji obuhvaćaju fizička i mehanička svojstva. Rezultati su pokazali kako radilišta označena brojevima 1 i 5, na kamenolomima Dehbid i Shayan, imaju najbolja svojstva postizanja većega brutoiznosa (4,95 i 3,2 m2 /sat) i netoiznosa (2,67 i -0,36 m2 /sat) proizvodnje