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Studi Adsorpsi Sianida dari Tailings Pengolahan Emas dengan Metode Resin-In-Pulp Ninik Lintang E.W.; Cut Shafira; Palguno Helyoso
Prosiding Seminar Nasional Teknik Kimia "Kejuangan" 2016: Prosiding SNTKK 2016
Publisher : Seminar Nasional Teknik Kimia Kejuangan

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Cyanidation is an efficient and inexpensive gold extracting process from ore, allowing gold recovery from low-grade ore carried out economically. The disadvantage of cyanidation process is the generation of highly toxic cyanide-containing tailings. Such tailings need to be treated prior to disposal, in order to comply with environmental requirements. There are two methods to overcome cyanide-containing tailing, by recycling and recovery. Cyanide recovery will eliminate the cyanide destruction cost and will reduce fresh cyanide purchasing cost. Cyanide adsorption (as part of Hannah Process) has been studied using batch adsorption techniques, to examine the contact time, adsorbent dose, and maximum adsorption capacity of Lewatit U-SO4 resin for cyanide removal. Results revealed that adsorption rate initially increased rapidly, and the optimum removal efficiency was reached within two hours. Further increase in contact time did not show significant change in equilibrium concentration; that means, the adsorption has reached equilibrium. The adsorption isotherms could be fitted well by the Langmuir model. The  RLvalue in the investigation was less than one, indicating that the adsorption of cyanide onto the  resin is favorable. The resin optimum dose was 44 g/L and  the maximum capacity was20 mg CN/g resin, equivalent to 0.846eq/L resin. 
Jurnal Kimia Riset Vol. 7 No. 1 (2022): June
Publisher : Universitas Airlangga, Campus C Mulyorejo, Surabaya, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20473/jkr.v7i1.35712


The processing of laterite ore by pyrometallurgy requires high temperatures whereas the Atmospheric Acid Leaching (AAL) method can be performed below 100 ℃ although its nickel recovery is inconsistent. This research aims to determine the effect of sulfuric acid concentration on nickel recovery and to determine nickel recovery after extract purification by precipitation of non-nickel metals. AAL was performed with an operating temperature of 95 °C, an operating time of 5 hours, an ore-to-solvent ratio of 0.05 g/ml, a particle size of ± 200 mesh, and sulfuric acid concentration variation of 0.2–1 M. Iron precipitation was completed with a pH variation of 0.5–3.8 by the addition of ammonia. The result showed that the concentration of sulfuric acid increased nickel recovery. The nickel recovery reached 96.43% at a concentration of sulfuric acid of 1 M. Furthermore, after extract purification, nickel recovery reached 50.61%, which was achieved at an optimum pH of 3.2.
Effect of Process Variables and Zeolite Adsorbent in Coffee Bean Drying Bambang Soeswanto; Ninik Lintang Edi Wahyuni; Ghusrina Prihandini; Yusuf Pratama; Taufik Akbar Firmansyah; Dewi Widyabudiningsih
Jurnal Internasional Penelitian Teknologi Terapan Vol 4 No 1 (2023): April 2023
Publisher : Bandung State Polytechnic (Politeknik Negeri Bandung)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35313/ijatr.v4i1.100


Green coffee beans to be stored for transportation must meet storage quality standards, especially the maximum moisture content of 12.5%, so the drying process must be carried out to achieve quality standards, but still economical. The study aims to obtain optimum operating conditions on the drying of Arabica-type coffee beans using a fluidized bed dryer assisted by zeolite adsorbents in a separated fluidized bed prior to heating, as well as calculating the energy consumption of blowers and air heater. The operating conditions were varied, namely air flow rate of 1.79 – 2.29 m/s, air temperature of 45 o C, 50 o C, and 55 o C, zeolite adsorbent mass of 150 g, 175 g, and 200 g. The coffee beans quality tests carried out were the moisture, carbohydrates, protein content, and the visual appearance of the beans. The results show that the optimum drying process of coffee beans resulting a minimum protein and carbohydrate damage are the air velocity of 2.1 m/s, air temperature of 55°C, drying time of 240 minutes, and zeolite adsorbent mass of 150 grams, with energy consumption of 5.02 KWH (equivalent to 180 MJ/T). The addition of zeolite as much as 150 grams, 175 grams, and 200 grams as adsorbent was able to reduce the relative humidity (RH) of air by 16.65%, 18.60%, and 21.17% respectively. The drying rate of coffee beans is mainly influenced by air temperature (more predominantly) than the adsorption of air humidity by zeolite.