scholarly journals A review of indium recycling methods from LCD screen wastes

2021 ◽  
Vol 62 (3b) ◽  
pp. 80-93
Author(s):  
Luan Van Pham ◽  
Toi Trung Tran ◽  

Indium, one of the important rare metals, has drawn more and more attention due to its semiconductor and optoelectronic performance. The by-products of zinc refineries are used as the primary mineral resources for the commercial production of indium. Indium contents of these products usually vary in a range of 100÷200 g/t. However, as a main secondary source of indium, LCDs waste contains much higher contents of indium than that in mineral ores. LCDs waste may contain up to 1,400 g/t In (equivalent to 0.7 g/m2). The indium recovery process from LCD screen wastes undergoes three stages: dismantling LCD screens; separation of indium-containing ITO glass, and recovery of indium metal. This paper presents the characteristics of the indium recovery process from LCD screen wastes and the main techniques used in each stage of technology. From there, a few suitable specific indium recycling processes are proposed for the conditions in Vietnam.

2018 ◽  
Vol 762 ◽  
pp. 121-125 ◽  
Author(s):  
Agnese Stunda-Zujeva ◽  
Imants Kreicbergs ◽  
Olita Medne

Biological treatment of municipal and industrial wastewater becomes more common in EU countries. As a result, the amount of wastewater sludge increases. The political and economic situation in world is requiring new methods for recovery of non-renewable mineral resources. Sludge is great secondary source of many elements. The aim of this research is to summarize available techniques for sustainable utilization of industrial sludge and recovery of critical raw minerals (CRMs). The most common sustainable method is using treated sludge as fertilizer in agriculture due to high content of P, N, C and microelements. However, this method has many restrictions, e.g. it can contain toxic substances or lack of appropriate land. Thermal sludge treatment methods like pyrolysis have developed crucially in last decade and pyrolysis units for sludge treatment are commercially available now. Pyrolysis becomes the most sustainable method due to recovery of CRMs and better energy recovery comparing to incineration.


2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Eko Ariyanto ◽  
Yuyun Niyati ◽  
Dian Kharismadewi ◽  
Robiah Robiah

Wastewater from the fertilizer industry contains a high concentration of PO43- and NH4+. Those ions formed deposits that frequently clogged the conduits and reduced the pump efficiency of the wastewater treatment plant. A high concentration of PO43- and NH4+ in this wastewater can be used as a secondary source of PO43- fertilizer through the recovery process into struvite compounds (MgNH4PO4.6H2O). In this research, Struvite was crystallized in Aeration Cone Column Crystallizer (ACCC) with Magnesium modified natural Zeolite (Zeo-Mg) as adsorbent. Research also has been done using the Batch process, and the results were used as basis variables in the ACCC system. Effects of Zeolite activation, amounts of Zeo-Mg (10 – 30 g), PO43- and NH4+reactant ratio (1:1 – 1:3), pH (6 – 9), and reaction time (0 – 60 minutes) to the removal percentage of PO43- were used as research parameters that analyzed in struvite crystallization process. Zeo-Mg and struvite produced were analyzed using scanning electron microscopy and energy dispersive X-ray spectroscopy. Research results in the ACCC system with Zeo-Mg as adsorbent showed that the percentage of PO43- removal was 65% in 16 minutes and followed pseudo-first-order reaction kinetics with a reaction rate constant of 0.21 min-1. The PO43- removal reached equilibrium at pH 8.10 after 28 minutes. Simultaneous removal of PO43- to formed struvite crystals using Zeo-Mg as an adsorbent and without the addition of Mg ions solution in the ACCC system is a novel process in wastewater treatment. Moreover, this PO43- recovery process can be implemented in the industrial scale due to the practical operation.A B S T R A KAir limbah industri pupuk banyak mengandung PO43- dan NH4+. Ion-ion ini membentuk endapan yang seringkali menyumbat aliran pipa yang menyebabkan penurunan efisiensi pompa di instalasi pengolahan air limbah. Kandungan PO43- dan NH4+ berkonsentrasi tinggi ini dapat dijadikan sumber sekunder untuk membuat pupuk PO43- dengan melakukan recovery sebagai senyawa struvite (MgNH4PO4.6H2O). Pada penelitian ini, struvite dibentuk menjadi kristal menggunakan Aeration Cone Column Crystallizer (ACCC) dengan adsorben zeolit alam yang telah dimodifikasi menggunakan ion magnesium (Zeo-Mg). Penelitian juga dilakukan dengan menggunakan proses batch, yang hasilnya dijadikan basis variabel pada sistem ACCC. Pengaruh pengaktifan zeolit, penambahan Zeo-Mg (10–30 g), rasio reaktan PO43- dan NH4+ (1:1–1:3), perubahan pH larutan (6–9), dan lamanya waktu reaksi (0–60) menit terhadap persentase penyisihan PO43- menjadi parameter yang dianalisis pada proses kristalisasi struvite. Zeo-Mg dan struvite yang dihasilkan dianalisis menggunakan scanning electron microscopy dan energy dispersive X-ray spectroscopy. Penelitian menggunakan ACCC menghasilkan persentase penyisihan PO43- dengan adsorben Zeo-Mg sebesar 65% dalam 16 menit dan mengikuti persamaan kinetika reaksi orde satu, dengan konstanta laju reaksi 0,21 min-1. Penyisihan PO43- mencapai kesetimbangan pada pH 8,10 setelah 28 menit. Proses pemisahan PO43- dengan adsorben Zeo-Mg menjadi struvite secara berkesinambungan pada sistem ACCC merupakan proses baru pengolahan air limbah. Selain itu, proses pemanfaatan kembali PO43- ini dapat diterapkan ke dalam skala industri karena kemudahan dalam pengoperasiannya.


2021 ◽  
Vol 1195 (1) ◽  
pp. 012031
Author(s):  
S M Anisuzzaman ◽  
M H Jumaidi ◽  
N N M Nasir

Abstract Used lubricating oil (ULO) is considered hazardous as it is able to cause pollution and affect the environment. The presence of degraded additives, contaminants, and by-products of degradation render ULO more toxic and harmful to health and environment than virgin base oils. Recovery of ULO generally comprises cleaning, drying, and adsorption in order to eliminate water, sludge, and impurities. As the ULO is one of the hazardous wastes generated in various industries, such as industrial and automotive, it should not be used or disposed of in ways that are harmful for the environment. Recovery of ULO carries out many advantages which includes lower environmental impact, higher energy saving and lower risks. The main objective of this paper was to thoroughly review various recovery process principles and treatment methods for ULO. Importance of ULO recycling and various techniques along with their limitations were also discussed. The significance of this study lies in reviewing the roles of adsorbent and adsorption reclamation processes of ULO and few promising adsorbents were earmarked for further study.


Author(s):  
Roger Waters

Coldpressed oil is one of the few by-products derived from the peel of the fruit which has continued to be economical to produce over the last couple of decades. Although the basic oil recovery process has been around for perhaps a century or more, technological advances have been made in more recent years in the development of more efficient processes and machine designs in terms of capacities, water conservation, effluent disposal, and automation. The basics of operating a coldpressed oil recovery system using some of the current technology will be discussed in this paper. Paper published with permission.


2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
Chiara Mollea ◽  
Fulvia Chiampo

Food processing by-products are usually cheap and abundant and can be source of valuable molecules of great interest to various industries like the pharmaceutical or the food ones. In this frame, the husks of roasted cocoa beans, that are a by-product of the cocoa processing industry, can constitute a source of pectin. The recovery process has been already defined at laboratory scale with boiling acid extraction (pH 2.5). This process is suitable to recover a quantity of pectin, expressed as anhydro-galacturonic acid (AGA), around 8 g AGA/100 g dry husks; this pectin is characterized by low degree of methylation (%DM around 31) and acetylation degree lower than 2%. In this paper the effects of some operative conditions on pectin quantity and quality were studied, in order to optimize the parameters that can make the process economically competitive: the in-excess quantities of solvents and operation time were reduced, without altering yield and pectin characteristics. In particular, the extract was concentrated by 13.3%, the ethanol for pectin precipitation was reduced (ratio extract to ethanol equal to 1:4), and it was also demonstrated that a single washing with 40% ethanol is sufficient to obtain a purified product.


2021 ◽  
pp. 34-40
Author(s):  
Guenter TIESS ◽  
Iryna SOKOLOVA ◽  
Serhii KLOCHKOV

The paper analyzes the changes in commodity market distortions, competing land use types, raw material demand for development, and rapid diffusion of key enabling technologies meeting the requirements of constant, dynamic development of major European industries. The author gives the relationship between the dynamics for mineral resources consumption growth, and changes in the conditions of production of these resources. Contains a critical review of methods for predicting the mineral resources dependency, including an estimated forecasting method based on guidelines for the evaluation of needs for natural resources and their substitutes.    One of the principles is comprehensive and integrated resource recovery. In a nutshell, this new approach argues that any operation should disturb a mine site only once and extract all useful materials using an optimised integrated flowsheet. This principle also requires that all by-products and residues are (re)used and that by-products and tailings at the end of life to be ‘future-proofed’, i.e. they should retain their ability to continue to be of value into the distant future where technology/economy may make feasible their use.    It is noted that access to and affordability of mineral raw materials are crucial for the sound functioning of the EU’s economy. A new 2020 list of critical mineral raw materials is presented and ways to compensate for the CRM deficit are described in detail.    Separately noted that the mineral policy is needed to be meticulously treated to facilitate company investment security, streamline permitting and access to minerals in a line with the European Green Deal, the Circular Economy Action Plan, the Bioeconomy Strategy and the European Industrial Strategy. Concerning, the latest steps towards Europe economically resilient by a framework for raw materials and the Circular Economy – creation of European Raw Materials Alliance recognized as particularly effective.    Global Industry Standard on Tailings Management represented as a robust, fit-for-purpose international standard for the safer management of tailings storage facilities.    The argument is given that since the land issue is one of the most delicate in a densely populated areas heavily dependent on agriculture, housing, infrastructure or other nonmineral development, a fair and equitable distribution of land is important for a mineral perspective.    There is also the need for strategic and open network between political, industrial and local communities through the exchange of information to enhance knowledge, experience and skills between stakeholders. Social acceptance of that idea is a fundamental element that must be addressed to develop a confl ict-free area for mineral development activities.    The conclusions indicate that we would like to emphasize that the main task of today is to create an effective system for monitoring the movement of raw materials along the entire added-value chain. The ability to quickly identify and respond to challenges in mineral policy will provide leadership in EU strategic technologies and industries. This process has already started with the creation of the European Raw Materials Alliance ERMA. State institutions, businesses, scientific institutions, and civil society in the close dialogue are able to ensure sustainable development and security of civilization as a whole. 


2013 ◽  
Vol 634-638 ◽  
pp. 3442-3445 ◽  
Author(s):  
Ci Yun Chen ◽  
Shu Ming Wen ◽  
Yong Jun Xian ◽  
Qi Cheng Feng ◽  
He Fei Zhao

Against the dwindling status of mineral resources at present, effective recycling of tailings resources is an effective way to alleviate the shortage of resources, and to improve enterprise efficiency. This study was aimed to recover iron from tailings of Yangla copper ore, Fe content of which was 15.31%, and the content of strong magnetic iron mineral was about 11%. Considering low content of weak magnetic iron mineral and its complex and costly recovery process, weak magnetic iron mineral did not be recovered, so strong magnetic iron mineral was only recovered in this study. Under no grinding condition, Fe recovery of 6.47% with iron grade of 60.87% was obtained. It effectively recovered strong magnetic minerals from tailings, and got enterprise increase additional revenue with good economic benefits.


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