scholarly journals ELIMINATION OF ADHESIVE IMPURITIES OF THE RECOVERED PAPER IN FLOTATION PROCESS

Wood Research ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 221-230
Author(s):  
Vladimír Kuňa ◽  
Jozef Balberčák ◽  
Štefan Boháček ◽  
Vladimír Ihnát

The article presents results of the elimination of sticky impurities from recovered paper in laboratory flotation of three pulp suspensions with different whiteness, obtained directly from the production line before entering flotation. A combination of commercial agents releasing undesirable substances from recovered paper and means for regulation and stabilization of froth and modified micronized bentonit was used. In the flotation purification of pulp suspension with a whiteness of 53%, the combination of Prodeink Extra, Prodeink AS10 and Hydrocol OT reduced the macrostickies content by 58%, the ash content decreased from 18.5% to 4.5%, the whiteness increased from 53% to 56.4% and the residual color content was reduced from 385 ppm to 294 ppm. The pulp suspension with a whiteness of 64% showed a reduction in the content of macrostickies by 66%, a reduction in the ash content by 23.2%, an increase in whiteness by 1.4% and a reduction in the residual color content from 245 ppm to 194 ppm. The pulp suspension with a whiteness of 68.3% showed a decrease in the content of macrostickies by 58.1%, the ash content decreased from 35.7% to 6.3%, the whiteness increased by 1.1% and the content of residual color decreased from 157 ppm to 117 ppm.

2014 ◽  
Vol 1010-1012 ◽  
pp. 1636-1639 ◽  
Author(s):  
Ji Hui Li ◽  
Li Qiang Ma ◽  
Yan Zhao Li ◽  
Wen Jing Li ◽  
Jian Wei Yue

The properties analyzing of flotation feed sample told that this fine coal sample is high-ash and hard-to-float coal slime. The ash reduction comparison of the step-by-step release flotation test with high intensity conditioning (HIC) or not, and the comparison of flotation test with HIC and adding depressant were made. The results showed that HIC can significantly improve the flotation effect for high-ash and hard-to-float coal slime. Comparing with the traditional step-by-step flotation process, if it meets the demand of ash content is 10.00% and 8.00%, the clean coal yield with HIC will increase 18 and 29 percentage points respectively; comparing with the effect of floatation adding depressant, HIC has more help to reduce the ash content and increase the yield of clean coal. In addition, HIC will save a lot of flotation reagents.


2016 ◽  
Vol 61 (1) ◽  
pp. 47-57
Author(s):  
Krystian Kalinowski ◽  
Roman Kaula

Abstract In the theory and a simulation technique of a coal flotation process a density function of a distribution of particles flotability is widely used. The characteristics of this type in the design of the flotation circuits as well as to optimize of the settings of the industrial flotation machines may be used. The density function of the distribution of the fraction f (k) based on the kinetics experiments to measure the recovery of material as a function of time in the laboratory flotation machines (in the batch coal flotation process) is determined. The problems of the determining of the flotability spectrum are relatively well resolved. An important problem is the determination of the concentrate quality. The concentrate quality directly depends on the ash content in the concentrate. In the paper a mathematical model of the separation of the mass of ash at the process of the kinetics of the batch flotation has been proposed. The research at different values of the air flow rate was carried out. The results of the analyses in tables and graphs are shown. The static characteristics of the single-cell of the flow flotation machine based on the characteristics of the distribution density of the fraction f (k) and the distribution of the ash content ak(k) were determined. Knowledge of these relationships will allow for a better assessment of the phenomena occurring in the enrichment process. This may be one of the basic information used in the supervisory control system of the flotation process.


Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3956 ◽  
Author(s):  
Changliang Shi ◽  
Gan Cheng ◽  
Shengnan Wang

Flotation tailings are by-products of coal preparation plants, which do not only occupy cultivated land but also cause pollution. The high ash content and low calorific value of tailings limit their applications. Deashing is the precondition for the reutilization of flotation tailings. However, it is more difficult to remove ash content from flotation tailings compared with raw coal. Based on the analysis of coal properties, the flotation performance of different collectors was compared in this study. Flotation flows and the mechanism of depressants were explored. The optimized flotation conditions were as follows: pulp concentration of 100 g/L, inflation rate of 0.25 m3/(m2·min), collector (C4) dosage of 300 g/t, frother dosage of 500 g/t, and revolving speed of 2200 rpm. The ash content of clean coal was also reduced by adding a depressant. The flotation performance was best when the amount of sodium hexametaphosphate (used as the depressant) was 4 kg/t; the recovery of clean coal was 71.88%, and the ash content was 10.64%.


TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.


TAPPI Journal ◽  
2015 ◽  
Vol 14 (3) ◽  
pp. 167-174 ◽  
Author(s):  
QIANQIAN WANG ◽  
J.Y. ZHU

Mixed office paper (MOP) pulp without deinking with an ash content of 18.1 ± 1.5% was used as raw material to produce nanofiller-paper. The MOP pulp with filler was mechanically fibrillated using a laboratory stone grinder. Scanning electron microscope imaging revealed that the ground filler particles were wrapped by cellulose nanofibrils (CNFs), which substantially improved the incorporation of filler into the CNF matrix. Sheets made of this CNF matrix were densified due to improved bonding. Specific tensile strength and modulus of the nanofiller-paper with 60-min grinding reached 48.4 kN·m/kg and 8.1 MN·m/kg, respectively, approximately 250% and 200% of the respective values of the paper made of unground MOP pulp. Mechanical grinding duration did not affect the thermal stability of the nanofiller-paper.


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Aulia Alfi

Virgin Coconut Oil (VCO) adalah bahan alami yang memiliki sifat antimikroba (antivirus, antibakteri, dan antijamur). Sehingga VCO dapat memberikan efek pengawet pada bahan makanan, salah satunya adalah roti manis. Penelitian ini dilakukan untuk mengevaluasi pengaruh VCO terhadap karakteristik (fisik dan kimia) dan umur simpan roti manis. Roti manis dianalisis secara fisik (tekstur dan porositas) dan kimia (kadar air, kadar abu, kadar lemak, kadar protein, dan kandungan karbohidrat), dan analisis umur simpan dengan FFA, uji organoleptik dan jamur setiap dua hari selama delapan hari penyimpanan di suhu ruang. Variasi perlakuan roti manis adalah dari rasio konsentrasi VCO: margarin: mentega, K (0%: 8%: 8%); A (4%: 6%: 6%); B (8%: 4%: 4%), C (12%: 2%: 2%); D (16%: 0%: 0%). Hasil penelitian menunjukkan bahwa VCO tidak memiliki pengaruh yang signifikan terhadap karakteristik fisik dan karakteristik kimia roti manis. Namun, VCO berpengaruh signifikan terhadap kadar air roti manis yang dihasilkan, roti manis K memiliki kadar air tertinggi (22,36%) dan berbeda dengan sampel roti manis lainnya. VCO secara efektif menghambat pertumbuhan jamur di roti manis pada konsentrasi 8%, 12%, dan 16%. Roti manis K dan A memiliki masa simpan 4 hari, sedangkan roti manis B, C, dan D memiliki masa simpan 6 hari.Kata kunci: VCO, roti manis, karakteristik, umur simpanABSTRACTVirgin Coconut Oil (VCO) is a natural ingredient that has antimicrobial (antiviral, antibacterial, and antifungal) properties. So that VCO can provide a preservative effect on food ingredients, one of which is sweet bread. This research was conducted to evaluate the effect of VCO on characteristics (physical and chemical) and shelf life of sweet bread. Sweet bread was analyzed physically (texture and porosity) and chemistry (moisture content, ash content, fat content, protein content, and carbohydrate content), and shelf life analysis with FFA, organoleptic and mold tests every two days for eight days of storage at ambient temperature. Treatment variations of sweet breads is from the ratio of the concentration of VCO: margarine: butter, K (0%: 8%: 8%); A (4%: 6%: 6%); B (8%: 4%: 4%), C (12%: 2%: 2%); D (16%: 0%: 0%). The results showed that VCO did not have a significant effect on the physical characteristics and chemical characteristics of sweet bread. However, the VCO has a significant effect on the water content of the sweet bread produced, sweet bread K has the highest moisture content (22,36%) and it is different from other sweet bread samples. VCO effectively inhibits the growth of sweet bread mold at concentrations of 8%, 12%, and 16%. K and A sweet bread has a shelf life of 4 days, while sweet breads B, C, and D have a shelf life of 6 days.Keywords: VCO, sweet bread, characteristics, shelf life


2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Bernaulli Putri Mulyanto ◽  
Yustina Wuri Wulandari ◽  
Akhmad Mustofa

      Brownies merupakan cake coklat yang terbuat dari tepung terigu, lemak, telur, gula pasir dan coklat. Metode pemasakan brownies ada dua yaitu pemanggangan dan pengukusan. Penelitian ini menggunakan tepung jewawut dan tepung maizena agar dihasilkan brownies kukus bebas gluten. Penelitian ini bertujuan untuk mengetahui formulasi tepung yang memiliki kadar protein tertinggi pada brownies dan untuk mengetahui lama pengukusan yang optimal sehingga menghasilkan brownies kukus tepung jewawut dan tepung jagung yang paling disukai. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan dua faktorial yaitu faktor pertama ratio tepung jewawut dan tepung jagung (50:50, 40:60 dan 30:70), sedangkan faktor kedua lama pengukusan (30 menit, 40 menit dan 50 menit). Hasil penelitian menunjukkan Brownies kukus tepung jewawut dan tepung jagung dengan ratio 50:50 dan lama pengukusan 50 menit merupakan ratio yang terbaik karena memiliki kadar protein paling tinggi yaitu 5.828%.  Pada perlakuan ini menghasilkan 19.967% kadar air, 1.585% kadar abu, 1.786% gula total, serta uji organoleptik terhadap warna 3.590 (coklat gelap), tekstur 3.340 (lembut), flavor jewawut 2.855 (sedikit terasa) dan kesukaan keseluruhan 3.285 (disukai). Kata kunci : Brownies, tepung jewawut, tepung jagung, kadar protein.  ABSTRACT      Brownies is chocolate cakes made from flour, fat, eggs, sugar and chocolate. There are two methods of cooking brownies namely roasting and steaming. This study uses millet flour and maizena flour to produced gluten free steamed brownies. This study aims to determine the best of flour formulated which has highest protein content in steamed brownies and to knew the optimal steaming time that produced the most favored  of  steamed brownies millet flour and  corn flour. This study used a completely randomized design (CRD) with two factorials, the first factor is ratio of millet flour and corn flour (50:50, 40:60 and 30:70), while the second factor was the duration of steaming process (30, 40 and 50 minutes). The result of the study showed steamed flour of millet flour and corn flour with ratio of 50:50 and with steamed process duration 50 minutes is the best ratio because it had the highest protein content of 5.828%.  In this treatment yielded 19.97% moisture content, 1.585% ash content, 1.786% total sugar and organoleptic test is 3.590 (dark chocolate) colors, 3.340 (soft) texture, 2.855 (slightly felt) millet flavors and 3.285 (preferred) overall preferences. Keywords :  Brownies, millet flour, corn flour, protein content


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