Smelting Research Articles

Temperature control of porous media burner based on advanced reduced instruction machine: PID algorithm and embedded processor

Against the backdrop of the rapid development of metal smelting processes, the requirements for reaction temperature control are gradually increasing, and the temperature control system for porous media burners based on advanced simplified instruction embedded processors has been developed. In this burner, the fuel is heated using a porous medium for conduction, which generates various complex data during operation and can overload conventional algorithms. To reduce the difficulty of algorithm operation, this study introduced an adaptive database into the proportional integral differential algorithm to classify data and establish a load balancer in the advanced reduced instruction algorithm, which is convenient for embedded processing of large amounts of data. To avoid the algorithm falling into local optima, this study merged the digital output module with it during temperature control to generate a fusion system. Finally, this study conducted experiments on the Porbu dataset and compared it with three systems such as generalized predictive control to verify the superiority of the fusion system. The temperature control accuracy of the four systems was 99.7%, 97.2%, 96.1%, and 93.5%, respectively, indicating that the efficiency of the fusion system performs the best among the four systems. The energy consumption of this system was 0.038 kWh, which performs best among the four systems. The experimental results indicate that the fusion system proposed in this study has the strongest performance and is suit-able for precise temperature control of porous media burners.

Impact of the Mednogorsk copper smelter on human health and soil environmental quality in Orenburg Region, Russia

Nonferrous metal smelting operations are a recognized source of metal accumulation in surrounding soils. In Mednogorsk, Russia, soil contamination results from atmospheric emissions from a local copper (Cu) smelter. This study aimed to assess health risks by analyzing the levels of Cu, arsenic (As), cadmium (Cd), lead (Pb), and zinc (Zn) in 20 Mednogorsk topsoil samples and three background area samples. The phytotoxicity of metals to Lolium perenne was also evaluated. The soil ingestion protocol of the US Environmental Protection Agency was used for health risk assessment. Phytotoxicity tests were performed on ryegrass using a standard protocol. The levels of Cu correlated with those of other elements, indicating that the smelter was the source. Of concern, the carcinogenic risk exceeded the 10-04 threshold in 85% and 15% of the samples for children under five years of age and adults, respectively. In addition, 60% of the samples exceeded the safe Pb threshold for children's health (80 mg kg-1). These risk levels are unacceptable and require specific intervention by the relevant authorities. However, only 20% of the samples showed high phytotoxicity, mostly in acidic soils (pH<4.0). This discussion focuses on the potential of soil phytostabilization to reduce human metal exposure, as the results provide valuable insights for managing metal pollution in regions affected by nonferrous smelter emissions worldwide.

Stability Analysis of Jet Deposition in Metal Melt Direct Writing Process

Stability Analysis of Jet Deposition in Metal Melt Direct Writing Process

Gold and silver: Noble solvents for the synthesis of superconducting boron-doped diamonds

The synthesis of diamonds in traditional growth systems based on Fe, Co and Ni does not allow overcoming the semiconductor level of boron doping of diamond, presumably because of a high affinity of boron to boride-forming metals. For the first time, noble metals that do not form borides—silver and gold—are used as growth media for the synthesis of heavily boron-doped diamonds at 8–9 GPa. Gold and silver are not catalysts for the transformation of graphite to diamond, whereas elemental boron is catalytically active at eutectic melting temperatures above 2500 K. It is found that the synthesis of diamond in AgB and AuB growth media starts at temperatures close to the melting temperatures of Ag and Au, 1600 and 1800 K, respectively. Calculations show that molten Au and Ag dissolve boron atoms without a significant change in the electronic structure of the solution, suggesting that the metal melts serve as a carrier for the boron catalyst. The resulting polycrystalline diamond contains dispersed inclusions of Ag and Au, as well as traces of boron carbide; the formation of borides is not detected. The transport measurements of the diamond samples reveal a transition to a superconducting state in the temperature range from 4.5 to 2.5 K. Raman spectroscopy confirms the heavy boron doping of diamond. Thus, we show that melts of “non-catalytic” metals that do not form borides can be effectively used to synthesize boron-doped conductive/superconducting diamonds at relatively low temperatures.

Development of an industrial solid waste ecological analysis model in Shanghai, China.

Amid China's rapid economic expansion, the country's industrial solid waste (ISW) problem is escalating. As each sector generates distinct types of ISW, a multi-indicator assessment of each sector is essential to address China's New Solid Waste Policy. To investigate the ISW situation of each sector and perform a comprehensive assessment, we formulate an industrial solid waste ecological analysis framework based on ISW generation and ISW flow in the sector. Various indicators (i.e., solid waste utilization coefficient, solid waste threat coefficient, and solid waste threat intensity) are employed to assess the utilization of solid waste generated for each sector, as well as the threat of solid waste originating in each sector to society. Ecological network analysis probes the interrelationships between diverse sectors. Taking Shanghai in 2017 as an example, the study indicates that some sectors (e.g., production and supply of electric power and heat power (EH) and metal smelting and rolling processing sector (MS)) exhibit higher direct ISW generation and the direct industrial solid waste value-added coefficient (SVAC) for common industrial solid waste (CISW). Specifically, the direct CISW generation of EH and MS is 539.21Mt and 277.00Mt respectively. The direct SVAC of EH and MS is 157.06kg/103RMB and 126.27kg/103RMB respectively. These sectors should prioritize reducing emissions at the source. Additionally, the threats to society from various sectors are relatively insignificant for the CISW, while for the hazardous waste (HW), all sectors pose a considerable threat to Shanghai's society. Moreover, some sectors (e.g., mining industry) exhibit the highest mutualism relationships in the CISW and the HW. Enhancing mining sector technologies is a vital strategy for mitigating ISW sources. Specifically, MI has 9 pairs of mutualism relationships in the CISW and 8 pairs in the HW. These insights will provide empirical evidence for tackling the ISW problem in Shanghai.

Market potential and the industrial sectors inclusion sequence in China's national carbon emission trading: From the perspective of maximizing gains

The carbon emission trading scheme (CETS) has been gradually introduced in China to control carbon emissions and boost economic and social development. The existing literature has evaluated the market potential of pilot CETSs or a certain industry, yet no study has focused on the industrial sectors to be covered in the national CETS to analyze trading flexibility and the sector inclusion sequence. This study presents an analytical framework for estimating market potential (i.e., potential gains and carbon emission reduction potential) and industrial sector inclusion sequences for China's national CETS using by-production models. Three simulation scenarios (i.e., no-trading scenario, power sector trading scenario, and multiple-industry trading scenario) and two trading modes (i.e., contemporary and intertemporal trading mode) are simultaneously considered. The novel evidences are: (i) There would be 39.93% (27.7 trillion CNY), 65.26% (273.0 trillion CNY) and 159.42% (666.7 trillion CNY) national aggregated potential gains of CETS in intertemporal power sector trading scenario, contemporary multiple-industry trading scenario and intertemporal multiple-industry trading scenario, and they would help save 3.60%, 5.18% and 6.05% of CO2 emissions reduction, respectively. (ii) CO2 emission permits would transfer from nonmetal minerals, ferrous metals, and electricity, to paper making, non-ferrous metals, petrochemicals, and chemicals under the intertemporal multiple-industry trading simulation. (iii) Based on the principle of potential gain maximization, it is recommended that the sector of smelting and processing of non-ferrous metals should to be included as the next sector in national CETS. The results show that national CETS has great market potential for achieving China's joint carbon control and economic growth goals.

Growing diamonds in the laboratory to investigate growth, dissolution, and inclusions formation processes

Replicating lithospheric diamonds experimentally helps reveal their histories at depth, which may be complicated by successive growth and dissolution episodes. Here, we present diamond growth and dissolution experiments to constrain the conditions of diamond formation and residence in the Earth’s lithosphere before their transport to the surface. Experiments were performed on mixtures of carbonates, natural lherzolite or MORB, water, diamond seeds, and with or without graphite using multi-anvil presses over a few hours to more than a day at conditions relevant to the lithosphere (7 GPa, 1300–1670 °C). We observed growth within a volatile-rich melt resulting from the miscibility of silicate-carbonate melt and aqueous fluid via the reaction: Carbonate minerals + Silicate minerals/glasses + H2O = [volatile-rich melt] ± minerals + Cdiamond + O2. In the absence of graphite, we observed diamond dissolution within the same hydrous-carbonate–silicate-bearing melts and under similar pressure and temperature conditions used to grow diamond, indicating that diamond formation requires an oxygen sink (graphite, metallic and/or sulphide melts). In dissolution experiments, we also observed resorption features similar to those described in lithospheric monocrystalline diamonds, which we thus attribute to mantle fluids and not to kimberlite-induced resorption during magma ascent. We show that dissolution and growth may alternate in the mantle, and that protracted periods are not necessary to explain natural diamond histories. During experimental growth, inclusions were trapped in diamonds as they are in nature. We observed both syngenetic (formed during growth, representing the parental fluid) and protogenetic inclusions (here particles from the capsule), indicating that both kinds of inclusions can be trapped within a single growth event. Our experiments confirm that inclusions trapped in natural diamonds do not necessarily represent remnants of their parental fluids and are not necessarily contemporaneous: two inclusions near each other within a single monocrystalline diamond may have different histories, and inclusions must be shown to have achieved chemical and isotopic equilibrium before being considered synchronous.

Analysis of the formation of the reactionary zone of interaction into the melt in converter aggregate and systematization of equations to determine the depth of its penetration

An important aspect in the operation of converters aggregates with top blowing technology is the influence high-temperature reactionary area of interaction on the thermal bricks in the converter aggregate. Provided the formation of irrational depth of penetration of the reactionary zone of interaction, there is a significant intensification of the wear of the thermal bricks on the bottom of the converter. One way to avoid such a phenomenon is a premature prognosis of the peculiarities of the formation of the reactionary zone of interaction and the depth of its penetration into the layers of the volume of metal melt. Today, there are much information about reactionary zone of interaction and equations for calculate it depth of penetration for different methods top and combine blowing technology in the converter. However, to date we need modern representation of the main types of geometric formation of the reactionary zone of interaction in the oxygen converter with top blowing from tuyere. Regardless of the design the multi-nozzles tip and the blowing modes. According to the purpose and tasks of the work, was offered three main types of the geometric formation of the reaction zone of interaction, in the oxygen converter with top blowing technology, regardless of the design of the multi-nozzles tip and the blowing mode: the separate formation of independent reactionary zones of interaction of certain geometric dimensions, the quantity of which is equal to the quantity of oxygen jets that directly act on the surface of the melt and penetrate its layers; the grouped formation of several united independent reactionary zone of interaction formed by the combination of two or more single reactionary zones created by independent oxygen jets; the united formation of one continuous reactionary zone of interaction due to the fusion of the external contours of all single reactionary areas of interaction, formed by independent oxygen jets. Into the single united reactionary zone of the interaction. In addition, was formed collection of equations to determine Lrzv – the depth of penetration of the reactionary zone of interaction of gas (oxygenes) jets into the melt of metal located in the working space of the converter bath. The separation of equations into collections was made according to the type of physical modeling what was used to obtain them. The first selection of equations obtained on the basis of processing the results of experiments with low temperature physical modeling consists of 13 equations. The second selection includes of equations obtained by processing the results with high temperature physical modeling experiments and consists of 7 equations

Revealing transmissions of atmospheric heavy metals hidden in the Chinese supply chain

Heavy metals (HMs) pose significant risks to human health and the environment. Identifying the sectors that play a significant role in the transmission of HMs has rarely been considered and represents an efficient method to control and manage HMs. By combining atmospheric HM emission inventories, the multi-regional input-output approach, and a betweenness-based method, this study revealed the transmission of HMs (comprehensively evaluated by the Heavy Metal Pollution Load, HMPL) in 2017. In 2017, 119.86 million tons of HMPL were transmitted through China's supply chain, and Cr was the main contributor to HMPL transmission. The results suggest that metal smelting is the primary contributor to HMPL transmission, and metal smelting in Jiangsu, Hebei, Henan, Shandong, and Anhui are the top five critical nodes. These results suggest that the sector's role changes dramatically with respect to HM control under this perspective. The role of HM emission-intensive sectors changed the most, as their production-based HMPLs accounted for 84% of the total HMPL; however, the HMPL transmitted by these sectors accounted for only 45% of the total. The critical HMPL transmission sectors identified in this study provide a basis for policy-making from a transmission perspective.

Иттриймен модификацияланған болаттардағы металл емес қосындыларды қалыптастыру

One of the promising areas in metallurgy is the study of the modifying abilities of rare earth metals (REM), among which yttrium is of particular interest. Having combined properties, yttrium acts as a complex modifier, so its use for modifying iron-carbon melts is of great interest. The paper studies the effect of modification of low-alloy steel with yttrium on the formation of non-metallic inclusions and the amount of modifier additives on the type and size of inclusions. Yttrium, interacting with a metal melt, forms refractory crystal systems of oxides, nitrides and carbonitrides. Such formation of forced centers not only improves the conditions of crystallization of liquid metal, but also has a positive effect on the processes of transformation in the solid state. This increases the overall level of metal quality, its ductility and strength in a wide temperature range, increases resistance to high-temperature corrosion

Numerical Simulation on Microwave Melting of Hastelloy C-276

Melting of metals is of utmost importance in the manufacturing industry as it is the primary manufacturing process to obtain the desired shape and size. microwave melting is a novel technique that uses electromagnetic wave radiation to heat materials. In the present work, the melting of Hastelloy C-276 inside a multimode microwave applicator operating at 2.45 GHz and 900 W input power, is explored in numerical and experimental. This results in a significant reduction in processing time and leads to lesser material wastage. The distribution of temperature, electric field, and resistive losses was analysed to understand the microwave melting of the Hastelloy C-276 sample. The study revealed that the melting time taken was ~440 seconds for microwave melting of Hastelloy C-276.

Quantitative characterization of resident’ exposure to typical semi-volatile organic compounds (SVOCs) around a non-ferrous metal smelting plant

To comprehensively characterize residents’ exposure to major semi-volatile organic compounds (SVOCs), samples of indoor floor wipes, size-segregated airborne particles, gaseous air, food, and paired skin wipes were simultaneously collected from residential areas around a large non-ferrous metal smelting plant as compared with the control areas, and three typical SVOCs (including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and halogenated PAHs (HPAHs)) were determined. Comparison and correlation analysis among matrices indicated PAHs were the major contaminants emitted from metal smelting activities compared to HPAHs and PCBs, with naphthalene verified as the most important characteristic compound, and their accumulation on skin may be a comprehensive consequence of contact with floor dust and air. While patterns of human exposure pathways for the SVOCs were found to be clearly correlated to their vapor pressure, dermal absorption was the major contributor (51.1–76.3%) to total carcinogenic risk (TCR) of PAHs and HPAHs for surrounding residents, especially for low molecular weight PAHs, but dietary ingestion (98.6%) was the dominant exposure pathway to PCBs. The TCR of PAHs exceeded the acceptable level (1 × 10−4), implying smelting activities obviously elevated the health risk. This study will serve developing pertinent exposure and health risk prevention measures.

Insights into the differences in metal anchoring mechanisms and the impact on HCN catalytic oxidation performance

Hydrogen cyanide (HCN) is often produced in various industrial processes, such as metal smelting, carbon fiber production, etc. Due to its highly toxic nature, it has significant harm to the human body and the environment. Catalytic oxidation can convert HCN into non-toxic N2, CO2 and H2O. In this study, we conducted a comparative evaluation of the catalytic oxidation of HCN using Cu, Co and Mn as catalyst active centers, and used in situ DRIFTS to explore the reaction mechanism of HCN catalytic oxidation. The difference in the anchoring state of different metals on the hydroxyl groups on the Al2O3 surface, mainly the difference in anchoring strength and hydroxyl consumption, determines the difference in the metal dispersion state, which in turn affects the oxygen activation ability and HCN oxidation performance. Under high loading conditions, compared to Co and Mn, Cu species are more fully anchored due to lower hydroxyl consumption, exhibiting higher dispersion and redox properties, so the 10Cu/Al2O3 catalyst performs well HCN oxidation activity.

OPERATING CONDITIONS AND STABILITY FIRE RESISTANT LINING SUBMERGED LANCE

To ensure the reliable and long—term operation of submersible lances used in the processes of bucket desulfurization of cast iron before converter processing, reliable means and appropriate conditions for supplying powdered desulfurizing reagents through nozzles of the lance tip, a rational scheme of refractory lining of the submersible lance and improvement of its operation modes are necessary. The purpose of the work is to study the characteristics of the destruction of the refractory lining of submersible lances, intended for desulfurization of iron—carbon melts by blowing powdery reagents deep into the ladle bath. To realize the goal, we used practical information on the researched question and the method of isothermal modeling of the hydrogas dynamics of a bucket bath using variable designs of the tips of stationary and rotating submersible lances. A comparative analysis and study of the features of the destruction of the lining of submerged stationary and rotating lances in the area of contact with the metal melt (below the "slag—metal" border) during gas injection into the bath was carried out using a 230—t pouring ladle model. During the experiments, T—shaped tips were used (for rotating and stationary lances) and tips with two spray pipe placed at an angle of 45 degrees to the axis of the lance (for stationary lances). Based on the results of data processing, mathematical models were obtained for each of the isolated zones on the lining surface of the submersible lance, and the statistical significance of the sample regression coefficients was checked. The nature and features of the destruction of the lining layer in each of the zones corresponding to the changes in the bath blowing conditions were established. New data were obtained regarding the intensity and depth of wear of the lining of the rotating submersible lance, depending on its speed of rotation and carrier gas consumption. It was established that under the investigated conditions of blowing the bath, the speed of rotation of the lance can be attributed to the factor most influencing the depth and intensity of wear of the lance lining.

Partitioning of nickel and cobalt between metal and silicate melts: Expanding the oxy-barometer to reducing conditions

Moderately siderophile elements (MSEs) are potential tracers of the thermodynamic conditions prevailing during planetary core formation because their metal–silicate partition coefficients (Dmet/sil) vary as a function of P, T, and oxygen fugacity (fO2). Those properties result in the production of planetary mantles with unique MSE depletion signatures. Among the MSEs, Ni and Co are reliable barometers in magma oceans because their Dmet/sil values are strongly correlated with pressure, decreasing by almost 3 orders of magnitude between 1 bar and 100 GPa. Current pressure-dependent expressions of Dmet/sil were calibrated based on experiments performed under relatively oxidizing conditions, mostly at fO2 slightly below the iron–wüstite Fe–FeO buffer (IW), which is relevant to the mantles of Earth and Mars. However, planets and asteroids formed under a wide range of redox conditions, from Mercury, the most reduced (∼IW − 5.5), to the most oxidized angrite parent body (IW − 1.5 to IW + 1). In this study, we performed and analyzed 38 metal–silicate partitioning experiments over a wide range of pressures (1 bar to 26 GPa) and oxygen fugacities (IW − 6.4 to IW − 1.9) to expand the available Ni and Co Dmet/sil values to reducing conditions. We then parameterized 255 Ni and 194 Co Dmet/sil values as a function of T (1573–5700 K), P (1 bar to 100 GPa), and fO2 (IW − 6.4 to IW + 0.2). We also modeled the evolution of Ni and Co Dmet/sil values along the liquidus of a chondritic mantle at various P and fO2 conditions to investigate the thermodynamic conditions of various planetary bodies’ magma oceans. The P and fO2 conditions we obtained for Earth, Mars, the Moon, and Vesta are consistent with previous studies using similar methods, and the pressure during core formation is strongly correlated to planetary size. Finally, we also applied our model to several achondrite parent bodies; our results indicate a wide variety of objects, from the asteroid-sized, oxidized angrite parent body to the planet-sized, highly reduced aubrite parent body.

Numerical Modeling of Water Jet Plunging in Molten Heavy Metal Pool

The hydrodynamic and thermal interaction of water with the high-temperature melt of a heavy metal was studied via the Volume-of-Fluid (VOF) method formulated for three immiscible phases (liquid melt, water, and water vapor), with account for phase changes. The VOF method relies on a first-principle description of phase interactions, including drag, heat transfer, and water evaporation, in contrast to multifluid models relying on empirical correlations. The verification of the VOF model implemented in OpenFOAM software was performed by solving one- and two-dimensional reference problems. Water jet penetration into a melt pool was first calculated in two-dimensional problem formulation, and the results were compared with analytical models and empirical correlations available, with emphasis on the effects of jet velocity and diameter. Three-dimensional simulations were performed in geometry, corresponding to known experiments performed in a narrow planar vessel with a semi-circular bottom. The VOF results obtained for water jet impact on molten heavy metal (lead–bismuth eutectic alloy at the temperature 820 K) are here presented for a water temperature of 298 K, jet diameter 6 mm, and jet velocity 6.2 m/s. Development of a cavity filled with a three-phase melt–water–vapor mixture is revealed, including its propagation down to the vessel bottom, with lateral displacement of melt, and subsequent detachment from the bottom due to gravitational settling of melt. The best agreement of predicted cavity depth, velocity, and aspect ratio with experiments (within 10%) was achieved at the stage of downward cavity propagation; at the later stages, the differences increased to about 30%. Adequacy of the numerical mesh containing about 5.6 million cells was demonstrated by comparing the penetration dynamics obtained on a sequence of meshes with the cell size ranging from 180 to 350 µm.

On the Mechanisms of the Cardiotoxic Effect of Lead Oxide Nanoparticles

Lead compounds are one of the most common pollutants of the workplace air and the environment. In the occupational setting, the sources of their emission, including in nanoscale form, are various technological processes associated with lead smelting and handling of non-ferrous metals and their alloys, the production of copper and batteries. Both lead poisoning and lead exposure without obvious signs of poisoning have a detrimental effect on the cardiovascular system. The purpose of this research was to investigate the mechanisms of the cardiotoxic effect of lead oxide nanoparticles (PbO NPs). The toxicological experiment involved male albino rats subchronically exposed to PbO NPs (49.6 ± 16.0 nm in size) instilled intraperitoneally in a suspension. We then assessed post-exposure hematological and biochemical parameters of blood and urine, histological and ultrastructural changes in cardiomyocytes, and non-invasively recorded electrocardiograms and blood pressure parameters in the rodents. Myocardial contractility was studied on isolated preparations of cardiac muscles. We established that PbO NPs induced oxidative stress and damage to the ultrastructure of cardiomyocytes, and decreased efficiency of the contractile function of the myocardium and blood pressure parameters. We also revealed such specific changes in the organism of the exposed rats as anemia, hypoxia, and hypocalcemia.Graphical

Simulation of Heat Transfer during Paraffin And Gallium Melting and Solidification Processes Utilizing Star CCm+

Energy storage systems are essential as the world works to minimize its dependency on fossil fuel energy for environmental and economic reasons. Because of their high capacity for latent heat storage. The numerical study of benchmark cases of solidification and melting was undertaken, and the results of these investigations are presented in this project. Numerical analysis is conducted to examine the brief solidification process of a pure liquid phase-change material within a rectangular enclosure when natural convection is present. The horizontal boundaries are both taken to be adiabatic, with one vertical barrier maintained at a temperature below the material's melting point and the other above. In this work, a numerical investigation of the melting of wax (namely N-octadecane) is presented. The numerical simulations of the experiments were carried out using STAR CCM+, and the results were compared with the results of other numerical simulations (FLOW 3D). The numerical simulations of gallium melting were carried out with a commercial code, STAR CCM+, which captures the solid-liquid interface with a fixed grid. This software captures the solid-liquid interface for phase change simulations in complex geometries with the enthalpy formulation technique. In addition, it demonstrates that computational fluid mechanics has reached a state of development where it permits reliable flow computations with solidification and melting. Casting with metal melts can be studied to provide information to engineers during the design process of new casting tools. The available simulation tools can also be used to predict existing casting processes and determine the origins of defects. The key findings are as follows: The interface shape during the solidification of gallium from above is always determined in large part by anisotropy in heat conductivity and interface growth morphology. Natural convection in the liquid slows down the rate of melting and adds more complexity to the morphology and transport mechanisms at the interface.

Carbon leakage or carbon reduction? Carbon emission effect of the production relocation of metal smelting industry in China

AbstractThe metal smelting industry (MSI) is one of the major carbon emission sectors in China, and it is of great significance to clarify the mechanism and truth of the carbon effect of production relocation (PR) of MSI for reducing national carbon emissions. Based on this thinking and previous studies, we proposed two concepts of relative carbon emission effect (RCE) and absolute carbon emission effect (ACE) of PR, then developed models to explore the impact of PR of MSI (PRM) on national carbon emission between 30 provincial administrative units in China from 2007 to 2017. The study demonstrates that the PRM and its ACE and RCE is divergent across provinces and regions. Overall, the PRM is beneficial to national carbon reduction under both relative and absolute scenarios. Specifically, the transfer‐in PRM of most provinces in central regions is beneficial to national carbon reduction, while the transfer‐out PRM of many provinces in coastal areas has worst carbon leakage effect.

Nanostructural phase transformations in eutectoid reactions of binary alloys

It is shown that eutectoid reactions of binary alloys are nanostructural processes. The main phase, which decays during the eutectoid reaction, is formed during the crystallization of a metal melt of eutectoid composition. This process is nanostructured. In it, the main elements of microcrystals are the nanocrystals of the alloy components. During the eutectoid reaction, the microcrystals of the main phase disintegrate into nanocrystals. Microcrystals of the other two phases are formed from them.