Deli verable 5 Capacities Work Programme: FP7‐ENV‐2012 Grant agreement no.: 308549 Duration:...

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FP7 Capacities Work Programme: FP7‐ENV‐2012 Grant agreement no.: 308549

Duration: October 1, 2012 – March 31, 2017

D5.3‐Report on the performance and the impact of the mobile plant 1

Contents Preamble ......................................................................................................................................................... 2

1. Introduction ............................................................................................................................................ 2

2. Waste Process Data ................................................................................................................................ 4

2.1 Spent lamps Process ........................................................................................................................... 4

2.2 CRT Process ........................................................................................................................................ 4

2.3 Lithium ion batteries process ............................................................................................................. 5

2.4 Printed Circuit Board Process ............................................................................................................. 6

2.5 LCD Process ........................................................................................................................................ 7

2.6 Conclusion .......................................................................................................................................... 8

3 RISK ASSESSMENT OFTHE HYDROWEEE MOBILE PLANT ....................................................................... 9

4 LIFE CYCLE ANALYSIS ............................................................................................................................. 13

4.1 Environmental impact of the HydroWEEE‐DEMO mobile technology ............................................. 13




Preamble

This report describes in a short and exhaustive manner the mobile plant, its use and which impact will be achieved.

DOW

Task 5.3 – Performance verification and evaluation of results

First of all the technical performance will be assessed and compared with the detailed functional specifications of task 1.1.

The resulting products of the different products will be sold on the market to end-users to evaluate its market acceptance and achievable price. This will be essential for the business plan in WP7.

Also the social implications of the new technology will be assessed.

Finally a risk assessment (incl. health) and a Life Cycle Assessment will be carried out with the help of UNIVPM. Special focus will be given to assess the local solutions for the remaining residues of the innovative processes.

1. Introduction

The mobile plant was built for the treatment of the residues from traditional recycling of five WEEEs: CRT, LAMP, LIB, PCB and LCD. The specific hydrometallurgical processes were optimized thanks to the research activity of the three university partners of the HydroWEEE-DEMO project: Università Politecnica of Marche, Università degli studi L’Aquila, Università Sapienza of Rome.

Fig. 1.1 shows the mobile plant layout and 3D draw. Photos in fig. 1.2 show the plant allocation in the industrial site (GreenTronics –Alexandria Romania).

The main cores of the processing of fluorescent powder, residue of exhaust lamps recycling, was to achieve high recovery yields for critical metals, the rare earths, with high purity of the final product using easily handling operation; with the same purpose CRT (Cathode Ray Tube) powder was treated. In the case of Li-Ion batteries the aim was the recovery of cobalt like carbonate. Very promising is also the treatment of PCB (printed circuit board), for which the aim of the developed process is the recovery of copper and precious metals at high purity.

Concerning LCD, the main goal was the recovery of Indium from a fine fraction that comes from LCD panel grinding.




Accordingly, within this deliverable, all the procedures for waste treatment in the mobile plant are presented. In addition, the impact of the mobile plant is also presented, in terms of environmental impact and risk

CONTAINER 1 CONTAINER 2

a)

b)

Figure 1. 1 Mobile plant equipment in the two containers, a) layout and b) 3D visualization

Figure 1. 2 External view of the Mobile Plant

FP1

T1

R1 FP2

B1 S1

R2 R3‐1

R3‐2




2. Waste Process Data 2.1 Spent lamps Process

Spent Lamp powder treated in mobile plant showed a composition slightly different with respect the one used in lab-tests, in particular the content of yttrium was lower, but mercury was absent therefore no thermal treatment was necessary to remove it. Briefly procedure description is reported below.

1- sulfuric acid leaching was carried out at a solid concentration of 15% under continuous stirring of 200 rpm for 2 h at reaction temperature for rare earths dissolution in R1. The filtration step is applied (by FP1) for solid separation by leach liquors and then a washing with a certain volume of water is performed. All liquid (liquor and water) was sent to R2;

2- precipitation with oxalic acid for 1 h under continuous stirring of 200 rpm at room temperature was performed (in R2) on liquor in order to precipitate rare earth oxalates. This product is recovered by filtration (by FP2) and after washed with a washing with a certain volume of water;

3- the residual solution, after precipitation and filtration, was sent to wastewater treatment reactors (R3-1 and R3-2), part of this solution was re-circulated in leaching reactor. Wastewater treatment consists of a neutralization with lime (Ca(OH)2) for impurities removal. Suspension was filtered (by FP1), the solid is disposed and the residual water was used as fresh water for a new cycle of leaching.

The best Yttrium extraction yield, obtained in mobile plant, was about 75%, with a precipitation yield close to 98%. Yttrium oxalate purity, expressed like Y2O3, was around 85% close lab-value that is around 91%.

2.2 CRT Process CRT powder treated in mobile plant showed a composition quite similar with respect the one used in lab-tests. The procedure applied in mobile plant does not include the zinc recovery, and it is the same procedure applied to lamp treatment. Briefly, the procedure description is reported below.

1- sulphuric acid leaching was carried out at a solid concentration of 15% under continuous stirring of 200 rpm at reaction temperature for rare earths dissolution in R1. Leaching time was increased from 2 to 3h to improve metal extraction yield. The filtration step is applied (by FP1) for solid separation by leach liquors and then a washing with a certain volume of water is performed. All liquid (liquor and water) was sent to R2;

2- precipitation with oxalic acid for 1 h under continuous stirring of 200 rpm at room temperature was performed (in R2) on liquor in order to precipitate rare earth oxalates. This product is recovered by filtration (by FP2) and after washed with a washing with a certain volume of water;

3- the residual solution, after precipitation and filtration, was sent to wastewater treatment reactors (R3-1 and R3-2), part of this solution was re-circulated in leaching reactor.




Wastewater treatment consists of a neutralization with lime (Ca(OH)2) for impurities removal. Suspension was filtered (by FP1), the solid is disposed and the residual water was used as fresh water for a new cycle of leaching.

Obtained Yttrium extraction yield was around 80% in the leaching process, with a Yttrium precipitation yield of around 94% as oxalate (corresponding to the final recovery of yttrium is about 65%). The yttrium oxalate-hydrate purity was less than 85%.

2.3 Lithium ion batteries process

For LIB a sample was kindly furnished from Saubermacher.

The sample characterization showed the presence of significant amount of Mn, Ni, and Co being the result of the mechanical treatment of a mixture of different types of lithium ion chemistries.

Even if the sample presents these impurities, not separable only by purification using precipitation, it was used for tests on pilot plant due to the great difficulties in finding other black powder of LiCoO2 batteries. In fact, dedicated physical pre-treatment units are not present in Hydroweee and Hydroweee-demo plants and due to flammable solvents inside LIB no one of the collectors contacted was able to physically treat the sufficient amount for pilot scale tests.

Also due to reduced amount of black powder the pilot plant built in Hydroweee was used for the treatment. In this pilot plant leaching unit has a total volume of 300 L (1:10 of the volume of mobile plant).

1- Black mass was leached (in R01) using 1:10 solid to liquid ratio with H2SO4 1.2 M and H2O2 2.5 M under magnetic stirring at 60°C, which is the maximum temperature for PE leaching reactor, increasing the timing to 4h in consideration of the slower kinetic due to the temperature reduction.

2- Solid/liquid separation (by FP01) was performed. Leach liquor was sent to tank S01 and after reactor drainage feed to R01 to the following step of purification. Residual solid is recyclable graphite (93% purity as C).

3- Leach liquor solution was treated with soda until pH 3.8-4 at equilibrium (at room temperature). Solid/liquid separation was performed (by FP01) giving: the purified leach liquor recovered in S01 and after feed to R01to Co recovery;

4- Na2CO3 was added to purified liquor with (0.61 Kg/Kg black mass) under stirring (0.5h) at room temperature.

Good recovery yield were obtained. Metal concentration in the final product mainly evidenced the increased concentration of Mn with respect to initial black powder. The purity of the final concentrate was evaluated as 16% of Co carbonate, 27% of Ni carbonate and 56% of Mn hydroxides.

The overall recovery of this target metals are 55, 52 and 66% for Co, Ni and Mn, respectively.




Wastewater treatment was not carried out due to the difficult to management also of this additional operation on a plant in which is present only one reactor to operate all the reaction steps.

2.4 Printed Circuit Board Process

Mobile plant experiments required material with granulometric size less than 2mm, these treatment were carried out on two different types of PCB, the first one is considerate “poor” PCB due it is low percentage of precious metals, the second one is called “rich” sample due it is higher contents of precious metals.

Element Poor [mg/Kg s.s.]

Rich [mg/Kg s.s.]

Au 43.4 306 Ag 571 690 Pt <5 Pd 38.9 42 Cu 32980 208000 Sn 20810 51100 Sb 66240 Fe 26570 23900 Zn 9110 27900 Al 45700 Pb 27800 Ni 2200

Table 2. 1 PCB powder composition

1- Cu dissolution (in R01) was performed by two-step counter-current leaching with sulfuric acid and hydrogen peroxide at a solid concentration of 15%, under continuous stirring of 200 rpm for 1.5h each batch. Filtration (by FP01) was applied for solid separation by liquid that was reused inside the process;

2- the leach liquor was treated with polyamine solution, for 30 minutes at a stirring rate of 200 rpm, to precipitate and recover tin;

3- leaching solid residue (tailing) was washed and used further for recovery of Au and Ag; the same procedure of filtration is used for solid precipitate recovery from solution; this precipitate is also washed to remove its content of residual solution and then the water is mixed with the solution;

4- liquid mix (liquor leach and tailing wash water) was treated with metallic Zn to cement Cu 5- leaching with thiourea and ferric sulphate in diluted sulfuric acid media is applied, in R01,

on the counter current leaching residue (tailing) at a solid concentration of 10% and stirring rate of 200 rpm for 1.1/2 h to extract gold and silver. filtration and washing procedure, as for the recovery of base metals, were performed. solution was reused for the leaching of another solid residue coming from counter current leaching process in the same conditions with a reagent solution make-up;




6- leaching solution was involved into the neutralization process with sodium hydroxide up to pH 2 which is afterwards followed by cementation with metallic zinc powder. Recovered sludge contains gold and silver.

The presence of electrolytic materials in the feed powder produces an increment of acid consumption necessary to extract quantitative amount of copper. One of the recommendations, to reduce raw materials consumption, is to remove the capacitors (in which these compounds are present).

Results obtained, from the two treatments of poor board, are quite similar and close to lab-scale data.

Main results in the treatment of rich material are:

- Cu extraction yield greater than 95%; - Cu recovery around 82% with purity of 85-86%; - Au extraction yield greater than 90%; - Au recovery around 75%; - Ag extraction yield around 42-45%; - Ag recovery around 45%;

2.5 LCD Process

Plant tests were carried out on a sludge that contains indium, coming from a plant for the recycling of monitors, through dismantling and wet grinding.. Due the nature of the raw material, the washing stage was omitted because during the wet-separation a washing of the powders also occurred.

1) leaching stage with sulfuric acid 2 M , 60°C 30 minutes, carried out (in R01) in a cross-current mode, in order to improve indium concentration in solution and to save the raw materials request.

2) cementation stage with zinc, 55°C, 20 min after pH adjustment at 3 with sodium hydroxide was carried out in laboratory to avoid high contamination (the phenomenon of contamination in this case is higher because the amount of In that is going to be recovered is very low).

Leaching carried out in the pilot plant produced results comparable with that obtained at the lab scale, with In leaching extraction efficiency around 55-60%. The best whole recovery, carried out at lab scale on a portion of solutions collected during the pilot plant procedures, was about 95%, confirming the previous results obtained in laboratory. The quality of the obtained product was not




so high, but this was probable due to the composition of initial material; indeed the sludge contains more contaminants than the ground LCD panel.

2.6 Conclusion Various campaigns of treatment for different e-waste streams (lamps powders, CRT fluorescent powders, LCD panel, LIB and PCB) were carried out, in order to implement developed processes on demonstration scale. These campaigns have provided good results in terms of elements recovery (rare earths and precious metals) and products purity.

Unfortunately, the economical feasibility depends on the market price of these metals and, sadly, in the recent years the price has dropped to some of the elements of interest of this project. For these reasons, dealing with REs recovery, in the last period the target of interest has been focused versus terbium recovery; however, in order to achieve Tb recovery in the mobile plant, it will be necessary to implement the plant by a thermal unit. Whereas, about PCB treatment, the main obstacle is represented by the supply of material suitable to the plant feed specifications (powder grain size and rich materials).




3 RISK ASSESSMENT OFTHE HYDROWEEE MOBILE PLANT

A correct process implementation should combine the technical and environmental optimization with a thorough risk assessment, since the scale-up of a treatment includes several risks for the workers. The main factors to consider are the probability that the hazardous source causes damage and the severity of the damage.

Considering the process steps, the following table reports the risks for all the involved operations.

Task Risk for health and safety Applied measures Possible support instruments

Placement of the cubes of liquid reagents (moving by forklifts)

Mechanical accidents (i.e. impact, crush, …) Possible release

Verify that the store and the adjacent areas are properly free from obstacles and that other people are not present in these zones.

Connection of the pipe lines to the liquid reagents cubes

Contact with strong acid and bases (i.e sulfuric acid, hydrogen peroxide and sodium hydroxide)

Supplied and use of DPI: face shield, safety goggles, chemicals resistant gloves, chemicals resistant suits. Drain lines before performing the operation.

SDS of the liquid reagents

Loading of the ferric sulfate (GHS hazards statements H302, 319, 335)

Harmful powder contact

Use the hopper located above the reactors. Supplied and use of DPI: face shield, safety goggles, chemicals resistant gloves, chemicals resistant suits.

Ferric sulfate SDS

Loading of ferrous sulfate (GHS hazards statements H302, 319, 315)

Harmful powder contact Use the hopper located above the reactors. Supplied and use of DPI:: face shield, safety goggles, chemicals resistant gloves, chemicals resistant suits.

Ferrous sulfate SDS

Loading of thiourea GHS (GHS hazards statements H302, 351, 316d, 411)

Harmful powder contact Use the hopper located above the reactors Supplied and use of DPI:: face shield, safety goggles, chemicals resistant gloves, chemicals resistant suits

Thiourea SDS

Table 3.7 (continue)




Loading sodium carbonate (GHS hazards statements H319)

Contact with a solution irritating for skin and eyes in case of accident

Supplied and use of DPI:: face shield, safety goggles, chemicals resistant gloves, chemicals resistant suits.

Sodium carbonate SDS

Loading sodium hydroxide (GHS hazards statements H314, 290)

Danger pellet contact Use the hopper located above the reactors Supplied and use of DPI: face shield, safety goggles, chemicals resistant gloves, chemicals resistant suits.

Sodium ydroxide SDS

Loading zinc

Not-harmful contact Use the hopper located above the reactors Supplied and use of DPI:: face shield, safety goggles, chemicals resistant gloves, chemicals resistant suits.

Zinc SDS

Loading oxalic acid (GHS hazards statements H302, 312, 318)

Harmful powders contact Use the hopper located above the reactors Supplied and use of DPI: gloves and visor FFP2.

Oxalic acid SDS

Loading of calcium hydroxide (GHS hazards statements H318)

Irritant compound contact Use the hopper located above the reactors Use gloves and safety goggles

Calcium hydroxide SDS

Powders dosage (moving by forklifts)

Hazardous waste powders contact Mechanical accidents (i.e. impact, crush, …)

Use the hopper located above the reactors Provide and use of masks FFP2-3, gloves and protection suits Correct harness and lifting loads

Filterpress unloading and cleaning

Contact with acidic solutions or solids

In the presence of localized suction. Use gloves and safety goggles and operate by a spoon. Verify the absence of the staff in the underlying area. Verify the presence of the target container.

Table 3.7 (continue)




Filterpress unloading and cleaning Contact with basic solutions or solids

In the presence of localized suction. Use gloves and safety goggles and operate by a spoon. Verify the absence of the staff in the underlying area. Verify the presence of the target container.

Handling of sludge boxes Contact with basic

solutions or solids Risks associated with overexertion

Supplied and use of DPI: Use gloves and safety goggles, acid-proof overallsWorking footwear

Plant operation – operating machines and other equipments (compressors and electric system)

Blast of the compressors, ejected objects and fire

Read carefully equipment manuals, perform ordinary and extraordinary maintenance of the machine

Plant operation – release of the liquids from piping and other components of the plant

Contact with acid and basic solutions Collision with equipments inside the plant

Intervening in plant with suitbale DPI: gloves and safety goggles, acid-proof overalls Working footwear The operator should be extremely careful during the operations

Ordinary maintenance Contact with acid and

basic solutions Collision with equipments inside the plant

Intervening in plant with suitbale DPI: gloves and safety goggles, acid-proof overalls Working footwear The operator should be extremely careful during the operations

Plant operation Fire for a malfunctioning

of heating reactors system Avoid the treatment in the periods in which the plant is not overseen. Inner temperature monitoring system. Available fire extinguisher.

Table 3. 1 Evaluation of risks at mobile plant




To conclude, the main risks are relative to the use of chemical reagents, other risk is relative to the possible of impact with the mechanical parts of the system during various operations, especially during maintenance. It is clear that the magnitude of the damaging event can be reduced adopting the individual safety devices, observing carefully the operating procedures and taking into account the machinery manuals.




4 LIFE CYCLE ANALYSIS

The LCA performed within the HydroWEEE Demo project has the general goal to identify the important environmental aspects and stages over the life cycle of the recycling processes of WEEE, based on the treatments developed within the project. The functional unit of this LCA is one cycle of treatment for each waste taken into account (LIB, Lamps, CRT, PCB and LCD). All data from the mass balances achieved within task 3.1 and the process analysis have been used as input for the inventory analysis. The life cycle impact assessment (LCIA) categories evaluated in this study are from the ILCD recommendations at midpoint. Only those that resulted to be significant from a first run of the LCA are considered (climate change, acidification, resource depletion). Data were elaborated using the GaBi 6 Professional software integrated with the EcoInvent database. ILCD recommendations were used for classification and characterization.

All described processes started from a pretreated and grinded waste and included all the steps of metals extraction and recovery.

4.1 Environmental impact of the HydroWEEE-DEMO mobile technology

The aim of this part of the report is to assess the environmental impact of the HydroWEEE-DEMO mobile technology. The carbon dioxide emissions associated to the HydroWEEE technology have been estimated through a LCA methodology (ISO14044), and compared to the primary production of the recovered metals. The evaluation has been focused on the category of global warming, since the climate change is a very topical issue, as confirmed by United Nations Climate Change Conference. Figures 4.1 and 4.2 evidence the positive effect on environment of the HydroWEEE technology, for the recovery of yttrium and other rare earths from fluorescent powders, residue of lamps and CRT recycling, for the recovery of cobalt from Li-ion batteries and of copper, gold and silver from printed circuit boards. For these two typologies of waste (batteries and boards), that currently are recycled in a big capacity pyrometallurgical plant located in the Northern Europe, the advantage associated to a local solution for metal recovery is also evidenced, as avoided emissions for waste transportation.




Figure 4. 1Carbon dioxide emissions of the HydroWEEE technology vs. primary production: recovery of yttrium and other rare earths from fluorescent powders residue of lamps (a) and cathode ray tubes (b) recycling treatments

Figure 4.2 – Carbon dioxide emissions of the HydroWEEE technology vs. primary production for the application on residues that currently are transported to a pyrometallurgical plant in Northern Europe: recovery of cobalt from Li-ion batteries (a) and of copper, gold and silver from printed circuit boards (b). Dotted bars represent the avoided emissions due to waste transportation.

As concerns the HydroWEEE technology for indium recovery from panels residue of LCD TV/monitor manual dismantling, it seems not to be environmentally favorable if compared to indium primary production (Figure 4.3a). This is undoubtedly due to the very low concentration of indium in the panel, around 100-150 mg/kg. However, a pre-concentration of indium up to about 5000 mg/kg (0.5%), achievable through a physical-mechanical treatment of the panel, would make the HydroWEEE technology preferable to primary production also for indium recovery (Figure 4.3b).




Figure 4.3 – Carbon dioxide emissions of the HydroWEEE technology vs. primary production, for the recovery of indium from panels residue of TV/monitor manual dismantling: (a) panel without any mechanical pre-concentration of indium; (b) after a preconcentration of indium up to 0.5%

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Deli verable 5 Capacities Work Programme: FP7‐ENV‐2012 Grant agreement no.: 308549 Duration:...

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