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1

The relationships between the kinetic grinding parameters with interstitial fillings and the liberation degree of a chromite ore

Umucu Yakup, Deniz Vedat, Gursoy Hakan Y., Tokcan Isıl, Arsoy Zeyni

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 5

art. no. 168254

EN

In this study, the relationships between the liberation degree and the kinetic breakage parameters of a chromite ore obtained from the Burdur (Türkiye) were examined under the laboratory conditions. Firstly, liberation degrees for chromite particles were determined by the particle counting method in a metal microscope for 4 different size groups. Secondly, the breakage parameter of chromite ore which was dry ground with a ball mill was obtained using standard test methods. Additionally, the model parameters were also determined for the fractional interstitial fillings (U) of the chromite sample. Thirdly, the kinetic grinding parameters were compared with the liberation degree of the chromite sample. As a result of the tests, a very good correlation was obtained with R2=0.998, and regression analysis in the grinding processing of the chromite ore was used to verify the validity of the relationship parameter of Si that was produced. To these, it was found that interstitial fillings (U=0.6, 0.8, 1.0, and 1.2) have an effect on the grinding.

2

Technological and economical investigation of glaze preparation using dry stirred media mill

Ergin Hasan, Yıldırım Yıldız, Çırpın Arife, Turgut Hatice, Kayacı Kağan

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 5

art. no. 166261

EN

Ceramic tiles are the most common building material for floor and wall coverings in many countries. Glazed tiles are produced from mixture of frits and some additional raw materials applied on the surface of green tiles and subjected to a firing process. A new method of processing of glaze that is dry stirred media mill was investigated in a pilot grinding plant. The produced glaze particle size, shape and surface area are measured. The comparison was made with the product of conventional wet discontinue ball mills using the same wall tile glaze recipes. The results indicated that dry stirred media mill can provide product that have finer particle size distribution, more stable product compared to the conventional wet ball milling. The glaze thermal expansion and optical properties such as colour (L, a and b parameters) of the produced glazes were measured and comparison was also made in details. Finally, the microstructural characteristics of the produced glazes were determined using scanning electron microscopy (SEM). The results have shown that dry stirred media mill enhances glaze properties and process economy considerably.

3

Analysing the impact of cutting force and vibration on surface roughness in external cylindrical grinding of SKH2 steel

Hoang Long, Nguyen Linh Tuan

Journal of Machine Engineering

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2023

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Vol. 23, No. 3

130--140

EN

The surface roughness of a part during external cylindrical grinding is directly impacted by cutting force and vibration, which are intermediate parameters. To improve the quality of finished parts, studying and controlling these parameters is essential. In this research, the Taguchi method combined with ANOVA analysis was utilized to analyse the effects of feed rate, cutting depth, and rotational speeds on cutting force and vibration amplitude. The test material used was SKH2 steel, which was heat-treated to a hardness of 60 HRC. The research aimed to investigate the relationship between cutting force, vibration, and surface roughness. The study concludes with an analysis of the influence of cutting force and vibration on the surface roughness of parts during external cylindrical grinding. The results show that as cutting force and vibration increase, the surface roughness of the workpiece in external grinding will also increase, and conversely when cutting force and vibration decrease, the surface roughness will decrease.

4

Mechanochemically Activated Shungite as an Additive to Improve Bitumen Characteristics

Zhambolova Ainur, Ongarbayev Yerdos, Kenzhegaliyeva Aliya, Abdikhan Dinmukhamed

Journal of Ecological Engineering

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2023

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Vol. 24, nr 11

218--226

EN

One of the urgent problems of improving the quality of road surfaces is to improve the properties of bitumen used as binders. For this purpose, various modifiers are used, which are mainly obtained synthetically. Modification of bitumen with natural raw materials is favorable from an economic and environmental points of view. The modification of road oil bitumen with samples of shungite from the Koksu deposit (Kazakhstan) was carried out in the work. The shungite samples were previously crushed by mechanochemical activation to improve their surface and adhesive properties. As a result of modification with shungite, an increase in the softening temperature and a decrease in the extensibility and penetration of bitumen were observed. The optimal amount of added shungite turned out to be 1 mass %. The shungite of carbonate origin on a mineral basis is more favorable as a modifier compared to samples of shale origin.

5

The numerical techniques application in the ball mill comminution process modelling

Pawlos Witold, Dominiczak Przemysław

Cuprum : czasopismo naukowo-techniczne górnictwa rud

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2023

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nr 1-2

47--53

EN

The preliminary results of comminution process numerical simulations have been presented in this paper. The numerical prediction has been based on discrete elements method (DEM) for solid modelling and smoothed particles hydrodynamics method (SPH) for modelling a continuous medium – liquid. The one way numerical coupling between solid and liquid has been applied. The ball mill working in production line in O/ZWR has been modelled. The considered ball mill is used to copper ore comminution process. The numerical calculations have been carried out for different mill rotation speed.

PL

W artykule przedstawiono wstępne wyniki numerycznych symulacji procesu rozdrabniania. Prognozowanie numeryczne zostało oparte na metodzie elementów dyskretnych (DEM), wykorzystanej dla modelowania cząstek stałych, oraz na metodzie symulacji hydrodynamicznej (SPH) dla modelowania w ośrodku ciągłym – ciecz. Zastosowano jednokierunkowe sprzężenie numeryczne pomiędzy fazą stałą a ciekłą. Młyn kulowy, zainstalowany w ciągu technologicznym ZWR, został wytypowany jako obiekt modelowania. Rozpatrywany młyn pracuje jako urządzenie rozdrabniające rudę miedzi. Obliczenia numeryczne przeprowadzono dla różnych prędkości obrotowych młyna.

6

Subsurface deformation and burr formation in nickel-based single-crystal superalloy under grinding

Liang Chunyou, Gong Yadong, Li Pengfei, Sun Jingyu, Jin Liya, Yin Guoqiang, Wen Xuelong, Bo Xin

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e126, 2023

EN

Machined subsurface and burr of nickel-based single-crystal superalloys (SXs) were identified as a key factor to the aero-engine industrial requirements concerning high service performance and the precision of edge geometry, in particular the finishing operations as grinding. To clarify subsurface deformation behaviors and the mechanisms of burr formation when grinding SXs, first, the present investigation predicted slip stresses acting on slip systems in workpiece subsurface under grinding based on the theory of resolved shear stress in single crystal, and correlated theoretical possible slip traces with experimental observed slip band systems. Second, grinding experiments on nickel-based SXs with [00-1]/[010], [11-3]/[332], [-110]/[111] and [-1-1-1]/[-110] orientations were performed to determine the anisotropy deformational behaviors of workpiece subsurface. Lastly, the unreported free surface of burr was adopted to investigate the formation mechanisms for side burrs and exit burrs during grinding. Results show that subsurface deformation patterns present anisotropy and resolved shear stress contribute to slip in nickel-based SXs. High shear density layers/zones consisting of interacted slip bands are found in grinding-induced sub-surfaces. Slip induced plasticity is the dominant deformation mechanism in the formation process of side burrs and exit burrs in grinding of nickel-based SXs.

7

Kinetics of copper leaching from direct‑to‑blister copper flash smelting slag by sulfuric acid

Gargul Krzysztof, Boryczko Bożena, Handzlik Piotr, Noga Piotr, Palimąka Piotr

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 1

art. no. e29, 2023

EN

Coppermaking from sulfide concentrates entails two major steps: smelting and converting. In continuous direct-to-copper smelting process these two steps are combined into one. The principal advantages of this process are: isolation of SO2 emission to a single, continuous, SO2-rich gas stream, minimization of energy consumption and minimization of capital and operating costs. Disadvantages of the process are that about 25% of the Cu entering a direct-to-copper smelting furnace ends up dissolved in the slag (when compared with < 10% in traditional Peirce-Smith converting) and the cost of recovering this Cu is significant. Decopperization process is based on the reduction of cuprous oxide and other metals, mainly lead and iron, in the liquid state in an electric furnace in the presence of coke and technological additives. This paper presents the results of laboratory tests on flash smelting slag leaching with sulfuric acid solutions. Hydrometallurgical treatment of the slag could be an alternative route to the presently used way of processing. The influence of a number of leaching parameters such as sulfuric acid concentration, amount of H2O2 added, liquid to solid phase (l/s) parameter and process temperature on the copper leaching efficiency was investigated. Under optimized process conditions, 95.6% of the copper contained in the original sample of slag was transferred into a solution. The experimental results obtained in the study were supplemented with the analysis of the kinetics of the copper leaching process from the flash smelting slag. The commonly known from the literature diffusion model and chemical reaction model were used. The activation energy of copper leaching from flash smelting slag was estimated in the range from 12.77 to 17.34 kJ/mol.

8

The latest innovations in wheat flour milling: a review

Dziki Dariusz

Agricultural Engineering

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2023

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Vol. 27, No. 1

147--162

EN

The milling process has evolved over time, employing various techniques to produce flour with different particle sizes and applications. This paper discusses the advancements in the wheat flour milling process and examines their impact on flour quality. The concept of wheat milling value is also introduced, which refers to the ability of wheat to produce flour with desirable properties and high yield. The importance of wheat cleaning in the milling process is highlighted, along with technological advancements such as color sorting machines and debranning of wheat grains before grinding, which facilitate efficient cleaning and increase flour yield. The progress of wheat conditioning in preparing wheat for milling is also discussed, along with current trends in grinding the wheat kernel. These advancements collectively contribute to enhancing flour quality, production efficiency, and overall milling performance.

PL

Sposób przemiału ziarna pszenicy ewoluował na przestrzeni ostatnich lat, poprzez wykorzystanie nowych technik, pozwalających na uzyskanie mąki o zmiennym składzie granulometrycznym i różnych zastosowaniach. W niniejszej pracy omówiono najnowsze trendy związane z produkcją mąki pszennej, analizując wpływ różnych metod i technologii na jej jakość. Omówiono także wartość przemiałową ziarna, pod kątem otrzymywania mąki o wysokim wyciągu i pożądanych właściwościach wypiekowych. Skupiono się również na innowacjach w procesie oczyszczania pszenicy, omawiając maszyny do sortowania ziarna względem barwy oraz urządzenia do obłuskiwania. Przeanalizowano także postęp w procesie kondycjonowania i rozdrabniania ziarna pszenicy. Wszystkie omówione innowacje przyczyniają się do poprawy jakości mąki oraz efektywności i wydajności produkcji mąki.

9

The effect of shape and roughness on flotation and aggregation of quartz particles

Guven Onur

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 6

art. no. 154021

EN

A combination of grinding and abrasion processes was applied to control the shape and roughness of quartz particles to investigate their roles in flotation recoveries and aggregation rates at different collector concentrations. The results showed that while the roundness values (Ro) of quartz particles varied in the range of 0.56-0.58 (Ro) at 480 and 1920 sec grinding, the roughness values of particles varied between 3.12-4.02 μm at 60 and 240 min abrasion. The flotation and aggregation tests showed while the flotation recovery increased from 31.3 % to 34.2 % in reverse proportion to their roundness values at 1x10-6 M DAH concentrations, a similar increasing trend from 34.1% to 38.1 % as a function of their roughness value from 3.12 μm to 4.02 μm. On the other hand, in the case of aggregation tests, while the turbidity values decreased from 40.6 NTU to 32.1 NTU at 1x10-6 M DAH concentrations for rounder particles, it was found as 36.2 NTU to 31.8 NTU for rougher ones. The overall results of this study indicated that tuning the morphology of quartz particles may be used to adjust both the flotation and aggregation rate of particles.

10

Modelling the power draw of tumbling mills : a comprehensive review

Golpayegani Mohammad Hasan, Rezai Bahram

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 4

art. no. 151600

EN

Optimizing power consumption in grinding, the most consumed stage in the mining industry, plays an influential role in reducing operating costs. Obtaining an efficient model to predict tumbling mills' power consumption accurately took the attention of researchers, mineral processing engineers, and tumbling mill manufacturers. This article comprehensively reviews the published mill power models and the most critical studies on this topic since 1919. Furthermore, the employed approaches for modelling the tumbling mills' power draw, the incorporated parameters into the developed models, the models' performances in predicting the industrial mills' power draw, and the potential gaps in the available literature are discussed. Moreover, based on the shortages identified in this review, some recommendations have been made to enhance the modelling mill power draw.

11

Influence of measuring process properties on phosphate rock slurry rheology based on Brookfield method

Chen Aoao, Zhang Qin

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 6

art. no. 156202

EN

This research aims to explore how the flotation process conditions influence the rheological properties of phosphate rock slurry. The apparent viscosity of phosphate rock slurry was measured by Brookfield DVNext rheometer. Different mineral types, grinding time, slurry mass concentration and reagent systems were adopted to study the viscosity behavior of phosphate rock slurry. The results showed that under the same conditions, the apparent viscosity of apatite and dolomite slurry was basically the same, and the apparent viscosity of the slurry after mixing the two minerals was basically the same as that of single mineral. For the same slurry concentration, the mineral particle size had a significant effect on the rheological behavior of the slurry, and its apparent viscosity increased exponentially with the decrease of particle size. In addition, phosphate rock slurry showed shear thickening fluids characteristics when the slurry concentration is 20%-40%, but changed to pseudoplastic fluid at high concentration (60%). Sulfuric acid as pH regulator and inhibitor had little effect on the rheology of slurry; when GJBW and NaOL were added as collectors, the rheology of slurry changed, and the effect of GJBW was more obvious.

12

Wpływ wybranych czynników na efektywność procesu szlifowania

Kotwis Mirosław, Żyłka Wojciech

Obróbka Metalu

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2022

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Nr 4

46--49

PL

W artykule przedstawiono dalsze rezultaty badań eksperymentalnych dotyczących wpływu wybranych czynników procesu szlifowania na stan powierzchni elementów obrotowych. Opis pierwszej części zawarty jest w numerze 3/2022. W tej części analizowano wpływ granulacji ziaren ścierniwa na chropowatość obrabianych powierzchni, a także związek między parametrami obciągania ściernicy a stanem powierzchni po obróbce. Stwierdzono zróżnicowaną istotność tych czynności.

EN

In the paper, further carried out experimental studies on the effects of selected grinding process factors on surface properties were presented. The description of the first part is given in No 3/2022. This section investigations the effects of granulation of abrasive grains on the surface roughness of the treated surfaces were contained. The relationship between the parameters of the grinding wheel dressing and the condition of the surface after machining were presented too. Different relevance of these factors was found.

13

Badania czynników determinujących efektywność procesu szlifowania

Kotwis Mirosław, Żyłka Wojciech

Obróbka Metalu

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2022

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nr 3

30--33

PL

W artykule przedstawiono analizę czynników determinujących rezultaty obróbki szlifowaniem powierzchni elementów maszyn. Przedstawiono także rezultaty badań eksperymentalnych dotyczących wpływu wybranych czynników tego procesu na stan powierzchni szlifowanych elementów obrotowych.

EN

In this paper the factors that determine the results of the grinding of machine elements were analyzed. Experimental research on the effects of selected process factors on the surface properties (its roughness) of rotating components were also presented.

14

Method of monitoring of the grinding process with lapping kinematics using audible sound analysis

Deja Mariusz

Journal of Machine Engineering

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2022

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Vol. 22, No. 4

71--81

EN

Utilising microphones as audible sound sensors for monitoring a single-side grinding process with lapping kinematics is presented in the paper. The audible sound generated during grinding depended on the cutting properties of electroplated tools with D107 diamond grains and different thicknesses of the nickel bond. The tool wear affected the obtained technological effects such as material removal rate and the surface roughness of Al2O3 ceramic samples. The relationship between the quantities that characterise the sound signal and the surface roughness of machined surfaces was examined with the use of spectral analysis of the sound signal in the frequency domain with a focus on the Ra parameter. The decreasing amplitude indicated a better surface finish, down to Ra = 0.23 μm. The developed method and the obtained results will facilitate the practical use of the electroplated tools in the lap-grinding technology without interrupting the process before obtaining the required surface roughness.

15

Effect of grinding conditions on the friction and wear performance of Ni based singlecrystal superalloy

Xu Yunchao, Gong Yadong, Zhang Weiqiang, Wen Xuelong, Xin Bo, Zhang Huan

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 2

art. no. e102, 1--16

EN

In this work, four types of surfaces were prepared as follows: untreated one, dry grinding (DG), wet grinding (WG) and minimum quantity lubrication grinding (MQLG) for Ni-based single crystal superalloy. The effects of grinding conditions on the surface roughness and microstructure evolution were studied. Dry sliding tests of ground surfaces were carried out at room temperature. Through the quantitative characterization of the wear rate, the area, width and depth of the worn profiles, the friction and wear mechanism of superalloy prepared by different grinding conditions were analyzed. The results show that the MQLG surface with low surface roughness and work hardening behavior has the best wear resistance. The element transfer behavior from the GCr15 ball to the worn surface was detected by EDS analysis. The wear type is mainly abrasive wear, accompanied by slight adhesive wear and oxidation wear. It is shown that high-quality surface with nanocrystalline and high density dislocation structure produced by MQLG improves the tribological properties of superalloy, which provide theoretical guidance for the surface machining of single crystal blade to reduce fretting wear.

16

Development of a grinding device for producing coal powder-raw materials of coal-water fuel

Kurytnik Igor P., Khassenov Ayanbergen K., Nussupbekov Ulan B., Karabekova Dana Z., Nussupbekov Bekbolat R., Bolatbekova Madina

Archive of Mechanical Engineering

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2022

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LXIX, nr 2

259--268

EN

This article proposes a method for grinding coal based on the use of the energy of a pulsed shock wave resulting from a spark electric discharge in a liquid. The main purpose of the scientific work is the development of an electric pulse device for producing coal powder, the main component of coal-water fuel. The diameter of the initial coal fraction averaged 3 mm, and the size of the resulting product was 250 μm. To achieve this goal, the dependence of the length of a metal rod electrode (positive electrode) on the length and diameter of its insulation is investigated. Various variants of the shape of the base (bottom) of the device acting as a negative electrode are considered, and an effective variant based on the results of coal grinding is proposed. An experimental electric pulse installation is described, the degree of coal grinding is determined depending on the geometric parameters. The optimal characteristics of the obtained coal powder have been established.

17

The Effect of the Wear Degree of Working Elements in a Jaw Crusher on the Operating Effectiveness of a Two-Stage Granite Grinding System

Dziubek Mateusz, Grygier Dominika

Tribologia

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2021

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nr 1

7--14

EN

The article presents an analysis of the influence of the wear degree of working elements in a jaw crusher on the crushing process and on the quality of the crushed material. The evaluation of the operating effectiveness of a technological system comprising two crushers was based on the quality indicator of the crushed product, i.e. on the share of irregular grains for a fraction with a mean grain size of 31.5/63 mm at each of the two stages of crushing. The wear degree was monitored by performing microscopic observations of the plates in the fixed jaw and by measuring the critical geometric characteristics of the crusher, e.g., tooth height, jaw size, and discharge opening size, during the entire service life of the crusher.

PL

W artykule przedstawiono analizę wpływu stopnia zużycia elementów roboczych kruszarki szczękowej na przebieg procesu rozdrabniania oraz jakość uzyskiwanego surowca. Jako wyznacznik oceny efektywności pracy układu technologicznego dwóch kruszarek przyjęto wskaźnik jakości produktu rozdrabniania, tj. udział ziaren nieforemnych, dla frakcji o średniej wielkości 31,5/63 mm na każdym z dwóch stopni kruszenia. Stopień zużycia monitorowano, prowadząc obserwacje makroskopowe płyt szczęki stałej oraz wykonując pomiary krytycznych cech geometrycznych kruszarki – wysokości zębów oraz wielkości paszczy i szczeliny wylotowej w ciągu całego okresu ich eksploatacji.

18

Proces rozdrabniania w młynie kulowym opisany teorią momentów statystycznych

Olejnik Tomasz P.

Technologia i Jakość Wyrobów

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2021

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R. 66

148--158

PL

W artykule przedstawiono wyniki badań mających na celu eksperymentalną weryfikację modelu rozdrabniania w młynie kulowym w oparciu o teorię momentów statystycznych. Badania kruszenia materiałów skalnych o różnej twardości przeprowadzono w młynie laboratoryjnym o objętości 6 dm3 . Dla określonych odstępów czasu pobierano próbki surowca z młyna i wykonano analizy granulometryczne, określając udziały procentowe produktu. Mielono cztery rodzaje materiału skalnego: gabro, kwarcyt, sjenit i piaskowiec żelazisty. Obliczono wartości momentów zerowych, momentów centralnych oraz współczynniki spłaszczenia i asymetrii. Zbadano zależności między tymi wartościami w funkcji czasu mielenia.

EN

Results of investigations which aimed at experimental verification of the model of grinding in a ball mill based on the theory of moments are presented in the paper. Grinding tests for rock materials with different hardness were carried out in a laboratory mill 6 dm3 in volume. Particle size distribution of the material was determined in specified time intervals. Four types of rock material were milled: gabro, quartzite, syenite and ferruginous sandstone. The values of zero moments, central moments and coefficients of flattening and asymmetry were calculated. Relationships between these values as a function of milling time were examined.

19

Ocena wpływu przygotowania próbek na uzyskiwane wyniki analiz pirolitycznych

Janiga Marek, Kania Małgorzata, Wciślak Agnieszka, Spunda Karol

Nafta-Gaz

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2021

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R. 77, nr 5

299--312

PL

Celem prac, których wyniki zaprezentowano w artykule, była ocena wpływu sposobu przygotowania próbek na wyniki analiz pirolitycznych: Rock-Eval, Py-GC-FID (chromatografia gazowa z detektorem FID) oraz Py-GC-IRMS (izotopowa spektrometria masowa z chromatografią gazową). Do rozdrobnienia próbek wykorzystuje się zazwyczaj moździerze oraz młyny kulowe. Przygotowano trzy próbki skał o większej zawartości węgla organicznego (łupki) oraz pięć o niższej jego zawartości (w tym dwie próbki z dolomitów i trzy z anhydrytów). Skały zostały zhomogenizowane i podzielone na trzy części. Każda część była mielona w odmienny sposób: ręcznie w moździerzu, w młynie kulowym przez 5 min i w młynie kulowym przez 15 min. W sumie wykonano 24 analizy Rock-Eval, 48 analiz Py-GCFID (dwie temperatury pirolizy, odpowiadające warunkom pirolizy Rock-Eval) oraz 24 analizy Py-GC-IRMS. Sposób zmielenia próbek do analiz Rock-Eval nie odgrywa roli. Wydaje się, że różnice w wynikach wskazują na wpływ błędu analizy oraz charakter próbki. Dla metodyki Py-GC-FID wpływ mielenia na wyniki desorpcji prowadzonej w temperaturze 300°C dla większości badanych próbek można uznać za nieznaczny i pomijalny. W temperaturze 500°C widać pewne korelacje, jednak nie są one tak jednoznaczne, aby odrzucić jeden ze sposobów przygotowania próbek. Dlatego istotne jest, aby wyniki analizować kompleksowo, uwzględniając zarówno skład grupowy, jak też dystrybucję produktów pirolizy. W przypadku analiz składu izotopowego (Py-GC-IRMS) również nie można stwierdzić różnic wartości δ13C związanych z różnym sposobem mielenia próbek. Podsumowując, wszystkie wyniki wskazują na znikomy wpływ sposobu mielenia próbek na wyniki analiz pirolitycznych. Pomimo to istotne jest, aby dla danej serii próbek wykorzystywać tylko jeden sposób przygotowania próbek.

EN

The aim of the work, the results of which are presented in the article, was to evaluate the influence of the method of sample preparation on the results of pyrolytic analyses: RockEval, Py-GC-FID (gas chromatography with FID detector) and Py-GC-IRMS (isotope mass spectrometry with gas chromatography). Mortars and ball mills are most often used to grind the samples. Three rock samples with a higher organic carbon content (shales) and five with a lower organic carbon content (including two samples of dolomites and three of anhydrites) were prepared. The rocks were homogenized and divided into three parts. Each part was ground: by hand in a mortar, in a ball mill for 5 minutes, and in a ball mill for 15 minutes. A total of 24 RockEval analyses, 48 Py-GC-FID analyses (two pyrolysis temperatures corresponding to RockEval pyrolysis conditions) and 24 Py-GC-IRMS analyses were performed. The grinding of the samples for the RockEval analyses is insignificant. The differences in the results seem to indicate the influence of the analysis error and the nature of the sample. For the Py-GC-FID methodology, the influence of milling on the results of desorption carried out at the temperature of 300ºC for most of the tested samples can be considered insignificant and negligible. At the temperature of 500ºC, various types of samples show some correlations, but they are insufficient to reject one of the methods of sample preparation. Therefore, it is important to analyze the results comprehensively, taking into account both the group composition and the distribution of pyrolysis products. In the case of the isotopic composition analyses (Py-GC-IRMS), also no differences in δ13C values related to different types of grinding samples can be found. Summarizing, all the results show a negligible influence of the method of grinding the samples on the results of pyrolysis analyses. Nevertheless, it is important that only one method of sample preparation is used for a separate sample series.

20

Nowe wodne ciecze obróbkowe do dogładzania oscylacyjnego jako alternatywa dla olei

Jemielniak Krzysztof

Mechanik

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2021

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R. 94, nr 4

20

PL

W celu redukcji negatywnego oddziaływania na środowisko i zwiększenia wydajności wielu producentów zastępuje się ciecze obróbkowe do szlifowania na bazie oleju cieczami opartymi na wodzie. Nadal jednak do dogładzania oscylacyjnego używa się cieczy olejowych. Tu przedstawiono badanie możliwości ich zastąpienia przez nową, wodną ciecz obróbkową.