Separation and Recovery of Acids from Waste Acid Mixture Mainly Containing Phosphoric Acid Discharged in Liquid Crystal Display Manufacturing Process

2003 ◽  
Vol 29 (4) ◽  
pp. 521-525 ◽  
Author(s):  
Junji Shibata ◽  
Masataka Morikawa ◽  
Norio Yoshikawa ◽  
Tomoko Yamada ◽  
Norihiro Murayama ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Phosphoric Acid ◽  
Manufacturing Process ◽  
Liquid Crystal Display ◽  
Acid Mixture ◽  
Waste Acid

scholarly journals Europium, Yttrium, and Indium Recovery from Electronic Wastes

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 777 ◽  
Author(s):  
Ernesto de la Torre ◽  
Estefanía Vargas ◽  
César Ron ◽  
Sebastián Gámez
Keyword(s):  
Liquid Crystal ◽  
Solvent Extraction ◽  
Oxalic Acid ◽  
Phosphoric Acid ◽  
Acid Solution ◽  
Rare Earths ◽  
Liquid Crystal Display ◽  
Modern World ◽  
Cathode Ray Tubes ◽  
Stoichiometric Amount

Waste electrical and electronic equipment (WEEE) has increased in recent decades due to the continuous advancement of technology in the modern world. These residues have various metals that are found in concentrations that make their recovery profitable. A group of metals of interest are the rare earths such as europium and yttrium, as well as semiconductors such as indium. Yttrium was recovered from cathode ray tubes that were manually dismantled. The resulted powder was leached with HNO3, and then the solution was submitted to solvent extraction with di-(2-ethylhexyl) phosphoric acid (DEHPA) using n-heptane as a diluent. For re-extraction, HNO3 was used again, and yttrium was precipitated by adding four times the stoichiometric amount of oxalic acid, reaching 68% yttrium purity. Indium was recovered from the liquid crystal display (LCD) screens for which the pulverized material was leached with H2SO4. Then, the indium sulfate was subjected to solvent extraction using DEHPA as an extractant, and diesel as a diluent. The re-extraction was carried out again with H2SO4, and the obtained acid solution was evaporated until the indium precipitated, reaching a recovery of 95%. The investigations that were carried out show that it is feasible to recover these metals in the form of oxides or phosphates with high commercial value.

scholarly journals Defect Cause Search Support System Using Ontology and Bayesian Network in Liquid Crystal Display Manufacturing Process

2016 ◽  
Vol 96 ◽  
pp. 859-868 ◽  
Author(s):  
Kouki Hamamoto ◽  
Akira Kitamura ◽  
Satoshi Taguchi ◽  
Shingo Watanabe ◽  
Hiroki Matsuno
Keyword(s):  
Liquid Crystal ◽  
Bayesian Network ◽  
Support System ◽  
Manufacturing Process ◽  
Liquid Crystal Display

scholarly journals Survey of Mura Defect Detection in Liquid Crystal Displays Based on Machine Vision

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1444
Author(s):  
Wuyi Ming ◽  
Shengfei Zhang ◽  
Xuewen Liu ◽  
Kun Liu ◽  
Jie Yuan ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Machine Vision ◽  
Defect Detection ◽  
Manufacturing Process ◽  
Liquid Crystal Display ◽  
Research Direction ◽  
Development Trend ◽  
Display Device ◽  
Low Contrast ◽  
Advantages And Disadvantages

Liquid crystal display (LCD) is a display device based on liquid crystal electro-optic effect, and LCDs have gradually appeared and have become an indispensable part of people’s lives. In the development of LCD technology, the detection of Mura defects is a key concern in the manufacturing process. The Mura defect is a kind of display defect with low contrast and an irregular shape. This study first explains the mechanism of Mura defects in the LCD manufacturing process and classifies typical Mura defects. Then, three main purposes for the defect detection of LCDs are compared, and the advantages and disadvantages are conducted. Following that, this research examines reviews the linked literature on image preprocessing, feature extraction, dimension reduction, and classifiers of Mura defects. Finally, the future development trend and research direction of Mura defect detection based on machine vision can be drawn by this study.

Sistem Kontrol Pengisian Air Otomatis Dengan Dua Sumber Suplai Berbasis Mikrokontroler (ATmega 8535)

2016 ◽  
Vol 1 (2) ◽  
pp. 84 ◽  
Author(s):  
Sumardi Sumardi ◽  
Muhammad Nur Anggoro
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystal Display

Sistem kontrol pengisian air otomatis dengan dua sumber suplai berbasis mikrokontroler merupakan sebuah sistem yang dapat digunakan untuk mengendalikan level air pada sebuah bak penampungan secara otomatis. Bahan dan alat yang digunakan dalam sistem kontrol berupa mikrokontroler ATmega 8535, sensor air, downloader DI-USB AVR ISP V2/DI-USB to Serial TTL, liquid crystal display, transisor, resistor, pompa air, adaptor 12 volt dc, saklar, dan program editor code vision avr. Metode yang digunakan dalam pembuatan sistem kontrol pengisian air otomatis ini adalah melakukan percobaan dan ujicoba peralatan secara langsung. Sistem kontrol ini bekerja dalam dua kondisi yaitu ketika air dalam bak penampungan melewati batas bawah maka bak penampungan akan terisi secara otomatis dan ketika telah mencapai batas atas yang ditentukan maka suplai air ke bak penampungan akan berhenti, selanjutnya ditambah pengaturan dari dua buah sumber air sebagai suplai yang akan bekerja sesuai dengan prioritasnya. Proses tersebut dilakukan oleh sensor bagian input yang berupa sensor air pada masukan sumber air yang kemudian diproses oleh mikrokontroler terprogram. Hasil percobaan menunjukkan sensor air berhasil memberikan logika Low atau High pada keluarannya sebagai fungsinya untuk memberikan sinyal masukan pada port mikrokontrol. Pada kondisi high, sensor air mampu memberikan nilai tegangan 4,89 Volt DC untuk digunakan sebagai masukan mikrokontroler. Dan pada kondisi low, sensor air mampu memberikan nilai tegangan 0,11 Volt dc sebagai masukan mikrokontroler ketika elektroda tehubung dengan common oleh media air. Driver Masukan terbukti dapat digunakan untuk menggendalikan kerja dari motor pompa 220 V AC dan lampu indikator 12 V DC. Hasil yang dari sistem kontrol pengisian air ini adalah terjadinya pengurangan kerugian yang ditimbulkan karena masalah ketersediaan air dan juga mempermudah kegiatan dalam pengendalian ketersediaan air. Kata kunci : Sistem kontrol, pengisan air otomatis, mikrokontroler, sensor air.

Activated carbon from molasses efficiency for Cr(VI), Pb(II) and Cu(II) adsorption: A mechanistic study

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Activated Carbon ◽  
Phosphoric Acid ◽  
Sugar Industry ◽  
Chemical Activation ◽  
High Surface ◽  
High Surface Area ◽  
Mechanistic Study ◽  
Acid Mixture ◽  
Maximum Adsorption Capacity ◽  
Good Potential

Activated carbon was prepared from molasses, which are natural precursors of vegetable origin resulting from the sugar industry. A simple elaboration process, based on chemical activation with phosphoric acid, was proposed. The final product, prepared by activation of molasses/phosphoric acid mixture in air at 500°C, presented high surface area (more than 1400 m2/g) and important maximum adsorption capacity for methylene blue (625 mg/g) and iodine (1660 mg/g). The activated carbon (MP2(500)) showed a good potential for the adsorption of Cr(VI), Cu(II) and Pb(II) from aqueous solutions. The affinity for the three ions was observed in the following order Cu2+ Cr6+ Pb2+. The process is governed by monolayer adsorption following the Langmuir model, with a correlation coefficient close to unity.

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