A full-priority flotation separation method for waste mixed plastics based on calcium sulfate pretreatment

A technology of mixing plastics and preferential flotation, applied in the field of waste plastic recycling, can solve the problems of changing the chemical structure of the plastic surface, high energy consumption, poor test reproducibility, etc., to achieve high selective separation, high recovery rate, and guaranteed process effects The effect of stability

Active Publication Date: 2021-07-09
CENT SOUTH UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The main problems of these technologies include the use of more chemical reagents that are not allowed by the environmental inspection department, high energy consumption, poor test reproducibility, and changes in the chemical structure of the plastic surface, etc.

Method used

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  • A full-priority flotation separation method for waste mixed plastics based on calcium sulfate pretreatment

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Effect test

Embodiment 1

[0049] Mixed plastic containing PMMA, PVC, PS, and ABS was cleaned, crushed, 5g of 3 to 5 mm particle diameter (PMMA: PVC: PS: ABS mass ratio 1: 1: 1), at 60 Under the conditions of ° C, contain 0.1 g / lcaso 4 The aqueous solution was stirred in 100 mL, the stirring time was 15 to 30 min, and the rotation speed was 800 to 1200 r / min, and the plastic particles were flotted. The suitable flotation conditions were pine oil alcohol 200mg / L, pneumant 700 ~ 800ml / min, the flotation time is 3 min, and the purity of PMMA was separated by flotation I was 97.1%, and the recovery rate was 97.3%. Ultrasound treatment (PVC, PS and ABS) is then subjected to ultrasonic treatment (PVC, PS and ABS), and then the second flotation is carried out to obtain 92.3% purity of the upper float PS purity, the recovery rate of 94.6%, and the sink mixed product ABS and PVC. Ultrasound treatment (power 100w, ultrasonic time 30min) was performed, and the treated plastic mixture was subtrained to give ABS...

Embodiment 2

[0051] Mixed plastic containing PVC, PS, ABS was cleaned, broken, and a plastic particles of 3 to 5 mm particle diameter (PVC: PS: ABS were 1: 1: 1: 1: 1: 1: 1: 1: 1: 1: 100ml under conditions of 45 ° C) Caso concentration is 0.2g / L 4 The aqueous solution is pretreated, the stirring time is approximately 10 min, the rotation speed is 200 ~ 300R / min, filtration, and the flotation separation is performed. The suitable flotation conditions are pine alcohol 200mg / L, the gas amount of 700 ~ 800 mL / min, floating In the selection time, 3 min was selected, and the PS purity of the upper floating product was 95.6%, the recovery rate was 96.8%, and then the lower backwrapping product (PVC and ABS) was easily treated (power 600W, ultrasonic time 10min), and then the second floating The concentration of ABS was 94.2%, 97.1% of the recovery rate, 97.5% pVC, and the recovery rate was 94.6%.

Embodiment 3

[0053] The mixed plastic containing PVC, ABS, and PMMA was cleaned, broken, 3 to 5 mm of plastic particles 2g (PMMA: PVC: ABS), 1: 1: 1: 1: 1: 1: 1: 1: 1: 1: Under the conditions of 40 ° C, 100ml concentration of Caso at 0.09g / L 4 The aqueous solution was treated for 10 min, and the stirring speed during treatment was 800r / min, filtered, and the flotation separation was performed. The suitable flotation conditions were pneumonol alcohol 200mg / L, the amount of air volume of 700 ~ 800 ml / min, flotation time 3 min, After the first flotation, the upper floating product PMMA was 96.4%, and the recovery rate was 94.7%. The sink mixture (PVC and ABS) passes through the ultrasonic treatment (power 150W, ultrasonic time of 25 min), then performing a second flotation to obtain a purity of the upper floating ABS purity purity purity of 91.6%, recovery rate of 92.8%, low sink product PVC purity 91.2%, recovery 99.8%.

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Abstract

The invention relates to a full-priority flotation separation method for waste and old mixed plastics based on calcium sulfate pretreatment. The technical solution is: crush the mixture of any two or more of the four waste plastics of PMMA, PVC, PS and ABS into mixed plastic particles, and the obtained particles are treated with CaSO 4 After pretreatment, PMMA, PS, ABS and PVC plastics are sequentially obtained through all-priority flotation separation. The method of the invention has the characteristics of simple operation, low cost, high separation efficiency, high recovery rate and purity, and the like.

Description

Technical field [0001] The present invention relates to a full-priority flotation separation method of waste mixed plastic based on calcium sulfate pretreatment, belonging to the field of waste plastics recovery. Background technique [0002] The rapid development of the plastic industry and a large number of uses have increased the number of waste plastics. Burning and landfill is a traditional way of treatment of waste plastics, which not only causes serious environmental pollution, but also causes a lot of waste of plastic resources. Therefore, recycling research on waste plastics has attracted high attention worldwide. The recycling of waste plastics mainly includes three stages: collecting, sorting, and recycling, and plastic sorting is the key and difficulty of recycling of waste plastics. Sate selection of waste plastics mainly include manual sorting, floating sort, flotation, selective dissolution, electro- and spectroscopy, etc. The manual sorting labor intensity is larg...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B29B17/02
CPCB29B17/02B29B2017/0203B29B2017/0248Y02W30/62
Inventor 王晖张迎霜王康宇杜一辰
Owner CENT SOUTH UNIV
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