Caustic Magnesia Production in Microfluid Furnace

2015 ◽  
Vol 1119 ◽  
pp. 529-532 ◽  
Author(s):  
Jan Spišák ◽  
Martin Truchlý ◽  
Ján Mikula ◽  
Vratislav Šindler

During procedure and heat treatment of magnesite in shaft and rotary furnaces, a great number of fine fractions are generated. In terms of MgO content, the fractions comprises the highest quality raw material. However, the desired degrees of calcination or sintering have not been achieved. For direct heat treatment of fine particles the microfluidic furnace has been proposed. The microfluidic furnace consists of the fluidization chambers in which the technology operations are being carried out. The furnace operates on the counter-current principle. The experiments of dust magnesite and flue gas calcination from rotary and shaft furnaces were carried out in the furnaces.

2019 ◽  
Vol 19 (3) ◽  
pp. 34-40
Author(s):  
S. Sots ◽  
I. Kustov ◽  
Y. Kuzmenko

It is proved the high effectiveness of using naked oats varieties Salomon and Samuel and hull-less barley variety Achilles as raw material for production new groats products with high biological value. Researched modes of pearling, water heat treatment and its impact on yield of pearled and flaked groats. The technological scheme of processing hull less barley and naked oats for producing groats, flakes, mixtures of groats and flakes were developed. Technology includes grain cleaning stage, grain water heat treatment, pearling, sorting of pearling products, pearled groat water heat treatment, mixing, flaking, drying, and control of end products. Studied hull-less barley characterized by high protein content 14,615,8 % and β-glucans – 6,8-7,4 %, has same to conventional dehulled grain mass fraction of lipids 2,1-3,8 % and starch – 57,6-60,5 %, low ash content 2,3-2,7%. Naked oats grain traditionally characterized by high mass fraction of lipids – 6,0-6,3 %,high mass fraction of protein - 14,9-15,4% and βglucans - 6,4-6,9% close to conventional dehulled grain mass fraction of starch – 59,3-61,6 % and ash – 2,1-2,3 %. It was found that the technologically expedient moisture content of hull-less barley and naked oats before pearling is 12-13 %. In the pearling the grain with this humidity depending on the duration of pearling yield of groat estimated to range between 6796 %. Increasing moisture content of grain before pearling to 14.0% does not significantly change the limits of yield values, and pearling grain with low moisture content of 10.5% leads to excessive grinding and formation of a significant amount of by-products and waste in the form of fine particles and husking bran.Technologically expedient moisture content of naked oats pearled groat before steaming stage are 15 % and the vapor pressure in steamer of 0.10 MPa. For the pearled barley groat most appropriate moisture content of before steaming is 20 % and the vapor pressure in steamer of 0.10 MPa.Steaming in this mode allows to obtain flaked groats with yield at 84 to 93%


Gefahrstoffe ◽  
2020 ◽  
Vol 80 (01-02) ◽  
pp. 19-24 ◽  
Author(s):  
M. Köhler ◽  
A. Ohle ◽  
M. Beckmann ◽  
S. Steinau ◽  
F. Tettich ◽  
...  

Der Anteil an Kremationen (Feuerbestattungen) nimmt in Deutschland seit Jahren zu und umfasst bereits mehr als 65 % aller Bestattungen. Grenzwerte für die Emissionen von Feinstaub oder die Anzahl ultrafeiner Partikel (UFP) existieren nicht und bisher sind auch keine systematischen Untersuchungen bekannt, welche Partikelemissionen in Krematorien auftreten. Daher kann zum aktuellen Zeitpunkt nicht beurteilt werden, ob es sich bei Krematorien um nennenswerte Feinstaubquellen handelt. Um diese Lücke zu schließen, wurden die reingasseitigen UFP-Konzentrationen in zehn Krematorien unterschiedlichen Bau- bzw. Modernisierungsjahres und mit verschiedenen Abgasreinigungstechnologien gemessen. Über die Kremationsdauer gemittelte UFP-Konzentrationen zwischen 1,19 · 10³ und 4,26 · 107 cm–3 wurden erfasst. Die höchsten Konzentrationen zeigten sich bei Anlagen mit Flugstromverfahren, deren Filtereinheiten unmittelbar vor der nächsten Revision standen. Bei Anlagen gleichen Typs mit gewarteten Filtereinheiten lag die mittlere UFP-Konzentration zwei Größenordnungen darunter.


Author(s):  
E.G. Astafurova ◽  
◽  
K.A. Reunova ◽  
S.V. Astafurov ◽  
M.Yu. Panchenko ◽  
...  

We investigated the phase composition, plastic deformation and fracture micromechanisms of Fe-(25-26)Cr-(5-12)Mn-0.15C-0.55N (wt. %) high-nitrogen chromium-manganese steel. Obtained by the method of electron-beam 3D-printing (additive manufacturing) and subjected to a heat treatment (at a temperature of 1150°C following by quenching). To establish the effect of the electron-beam 3D-printing process on the phase composition, microstructure and mechanical properties of high-nitrogen steel, a comparison was made with the data for Fe-21Cr-22Mn-0.15C-0.53N austenitic steel (wt. %) obtained by traditional methods (casting and heat treatment) and used as a raw material for additive manufacturing. It was experimentally established that in the specimens obtained by additive manufacturing method, depletion of the steel composition by manganese in the electron-beam 3D-printing and post-built heat treatment contributes to the formation of a macroscopically and microscopically inhomogeneous two-phase structure. In the steel specimens, macroscopic regions of irregular shape with large ferrite grains or a two-phase austenite-ferrite structure (microscopic inhomogeneity) were observed. Despite the change in the concentration of the basic elements (chromium and manganese) in additive manufacturing, a high concentration of interstitial atoms (nitrogen and carbon) remains in steel. This contributes to the macroscopically heterogeneous distribution of interstitial atoms in the specimens - the formation of a supersaturated interstitial solid solution in the austenitic regions due to the low solubility of nitrogen and carbon in the ferrite regions. This inhomogeneous heterophase (ferrite-austenite) structure has high strength properties, good ductility and work hardening, which are close to those of the specimens of the initial high-nitrogen austenitic steel used as the raw material for additive manufacturing.


2011 ◽  
Vol 284-286 ◽  
pp. 1431-1434 ◽  
Author(s):  
Jin Rui Zhang ◽  
Ru Wang

In order to utilization the molybdenum tailings which be deposited in large quantities. Test used it to prepare glass-ceramics as main raw material, TiO2 as nucleation agents and CaO-Al2O3-SiO2 system and wollastonite as the principal crystalline phase. Heat treatment system of glass-ceramics was based on the differential thermal analysis. The crystalline phase, microstructure and characteristics of glass-ceramics were analysis by XRD, SEM and physical, chemical properties test. The result shows that the performance of glass-ceramics was superior to the other types of building decoration stone.


Energy ◽  
2020 ◽  
pp. 119392
Author(s):  
Zhaohao Li ◽  
Dabin Mi ◽  
Heng Zhang ◽  
Haiping Chen ◽  
Zhenghao Liu ◽  
...  

2021 ◽  
Vol 17 (2) ◽  
pp. 127
Author(s):  
Nyoto Lestari ◽  
Helmy Purwanto ◽  
Muhammad Dzulfikar
Keyword(s):  

Perlakuan panas (heat treatment) didefinisikan sebagai kombinasi proses pemanasan dan pendinginan untuk mendapatkan sifat-sifat tertentu pada baja atau paduan lainnya. Salah satu proses perlakuan panas tersebut dengan proses quenching dan tempering. Proses ini dilakukan pada temperatur austenite 700 oC, 800 oC, 900 oC dengan media pendingin celup oli, kemudian di lanjutkan proses tempering pada temperatur 100 oC, 200 oC, 300 oC, dan 400 oC dengan waktu penahanan 15 menit. Hasil pengujian pada uji struktur mikro memperlihatkan bahwa fasa yang banyak terlihat adalah fasa perlit, sedangkan fasa martensit jarang ditemukan. Hasil pengujian kekerasan memperlihatkan bahwa nilai tertinggi adalah 591 HVN terdapat pada temperatur austenite 900 oC dan di tempering pada temperatur 200 oC. Hasil pengujian tarik mendapatkan Maksimal Stress tertinggi pada temperatur austenite 900 oC dan temperatur tempering 100 oC dengan nilai 961 MPa. Pengujian impak mendapat nilai 0,40J/mm2 yang terdapat pada temperatur austenite 900 oC dan temperatur tempering 400 oC. Proses tempering dapat menurunkan nilai kekerasan dan kekuatan tarik dan pada uji impak nilai kekerasan meningkat. Sementara hasil mikro struktur memperlihatkan bahwa jumlah fasa-fasenya hampir sama dengan  raw material.   


2014 ◽  
Vol 6 (2) ◽  
pp. 115-119
Author(s):  
Tri Hoang

This paper introduces an energy-saving biomass stove. The principle of energy-saving biomass stove is gasification. It is a chemical process, transforms solid fuel into a gas mixture, called (CO + H2 + CH4) gas. Emission lines in the stove chimneys typically remain high temperatures around 90° to 120°C. The composition of the flue gas consists of combustion products of rice husk which are mainly CO2, CO, N2. A little volatile in the rice husk, which could not burn completely, residual oxygen and dust will fly in airflow. The amount of dust in the outlet gas is a combination of un-burnt amount of impurity and firewood, usually occupied impurity rate of 1 % by weight of dry husk. Outlet dust of rice husk furnace has a normal size from 500μm to 0.1 micron and a particle concentration ranges from 200-500 mg/m3. Gas emissions is created when using energy-saving stove and they will be used as the main raw material in combustion process Therefore the CO2 emission into the environment when using the stove will be reduced up to 95% of a commonly used stove. Bài báo giới thiệu một bếp tiết kiệm dùng năng lượng sinh khối. Bếp tiết kiệm năng lượng thực hiện nguyên lý khí hóa sinh khối. Đó là một quá trình hóa học, chuyển hóa các loại nhiên liệu dạng rắn thành một dạng hỗn hợp khí đốt, gọi là khí Gas (CO + H2 + CH4). Dòng khí thải ra ở ống khói của bếp thông thường có nhiệt độ vẫn còn cao khoảng 90° ~ 120°C. Thành phần của khói thải bao gồm các sản phẩm cháy của trấu, chủ yếu là các khí CO2, CO, N2, một ít các chất bốc trong trấu không kịp cháy hết, oxy dư và tro bụi bay theo dòng khí. Lượng bụi tro có trong khói thải chính là một phần của lượng không cháy hết và lượng tạp chất không cháy có trong củi, lượng tạp chất này thường chiếm tỷ lệ 1% trọng lượng trấu khô. Bụi trong khói thải lò đốt trấu thông thường có kích thước hạt từ 500μm tới 0,1μm, nồng độ dao động trong khoảng từ 200-500 mg/m3. Lượng khí thải được sinh ra khi sử dụng bếp tiết kiệm năng lượng, sẽ được dùng làm nguyên liệu đốt cháy chính của quá trình đó. Do đó lượng khí CO2 thải ra môi trường khi sử dụng bếp tiết kiệm sẽ được giảm xuống 95 % so với sử dụng bếp thường.


2021 ◽  
Vol 1 (1) ◽  
pp. 51
Author(s):  
Alfan Ekajati Latief ◽  
Syahril Sayuti ◽  
Rakean Wide Windujati

 ABSTRAKTanto merupakan senjata tajam yang berasal dari Jepang dan merupakan senjata kedua bagi para Samurai di Jepang. Tanto biasa terbuat dari baja karbon menengah hingga baja karbon tinggi yang. Material baja yang digunakan untuk pembuatan Tanto dalam penelitian ini adalah baja AISI seri O1 karena memiliki karakteristik sifat mampu bentuk yang baik serat dapat dikuatkan melalui proses heat treatment. Material baja ini dibuat dengan proses tempa lipat  dengan variasi tempa empat lipatan dan satu lipatan. Pembuatan Tanto dan spesimen uji dilakukan dengan proses tempa lipat secara konvensional menggunakan tungku arang, dengan temperatur tempa rata-rata yaitu ±1200oC, kemudian dilanjutkan dengan quenching pada temperatur ± 850oC, serta tempering pada temperatur ±250oC. Penelitian ditujukan untuk mengetahui pengaruh dari proses tempa empat lipatan dan tempa satu lipatan terhadap sifat mekanik, yaitu kekerasan dan kekuatan impak serta untuk melihat perubahan pada struktur mikro. Hasil pengujian menunjukkan bahwa nilai kekerasan paling tinggi sebesar41HRC yang dimiliki oleh pada raw material, ,sedangkan nilai impak paling tinggi sebesar 224,02 Joule/cm² ayng dicapai oleh material dengan proses tempa empat lipatan, Fasa akhir yang ditemukan pada baja tempa empat lipatan adalah  bainit dan martensit, sementara  perlit dan ferit ditemukan  pada baja satu lipatan, dan lath martensit ditemukan pada pada raw material  Kata kunci: Pisau Tanto, Tempa lipat ,Quenching, Tempering, Uji Impak  ABSTRACT Tanto is a sharp weapon originating  from Japan and is the second weapon for Samurai in Japan. Tanto is usually made of medium carbon steel to high carbon steel. The material which is used in this research is AISI O1 series steel because of its high ability to be formed and also can be made tough through a heat treatment process. This steel is made by folding forge process, with variation in number of folding, which is 4 folds and 1 fold. The making of Tanto and test specimens was carried out by conventional fold forging processes by using a charcoal furnace, with an average forging temperature at ± 1200oC, continue with quenching at ± 850oC, and tempering at ± 250oC. The research is carried out in order to determine the effect of the four-folds forging and one-fold forging to the mechanical behavior, which are hardness and impact strength,  and also to see change in its micro structure. The test that have been carried out shows that the highest hardness value of 41 HRC owned by raw material, while the highest impact value of 224.02 Joules / cm² obtained by material with four layer forging process. Final phases that found in the four-fold forged steel are bainite and martensite, pearlite and ferrite found in one-fold forged steel. and lath martensite in found in the raw material. Keywords: Tanto Knife, Folding Forging, Quenching, Tempering, Testing, Impact Tests


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1308 ◽  
Author(s):  
Arnab Chakraborty ◽  
Răzvan Hirian ◽  
Gregor Kapun ◽  
Viorel Pop

Nanostructured alloy powders of SmCo5 + 10 wt% Fe obtained using recycled material were studied for the first time. The SmCo5 precursor was obtained from commercial magnets recycled by hydrogen decrepitation. The results were compared with identically processed samples obtained using virgin SmCo5 raw material. The samples were synthesized by dry high-energy ball-milling and subsequent heat treatment. Robust soft/hard exchange coupling was observed—with large coercivity, which is essential for commercial permanent magnets. The obtained energy products for the recycled material fall between 80% and 95% of those obtained when using virgin SmCo5, depending on milling and annealing times. These results further offer viability of recycling and sustainability in production. These powders and processes are therefore candidates for the next generation of specialized and nanostructured exchange-coupled bulk industrial magnets.


Sign in / Sign up

Export Citation Format

Share Document