Aluminium Foundries Circularity via Holistic Zeolite Production for Effluents Depuration

Introduction

The aluminium industry must face a definitive solution for the management of salt slag, included in the European Waste Catalogue as hazardous waste, to improve its still unperfected circularity. The EU produces 1Mt/y of salt slag, and its disposal is banned in most countries. Nowadays, the management of salt slag is a worldwide concern, and its valorisation is not yet solved.

Project Overview

Z-ONA4LIFE envisages a holistic approach to salt slag recovery for the Circular Economy, European Green Deal, and Sustainable Development Goals (SDGs). It focuses on a new circular zeolite (Z-ONA) production technology and its exploitation to overcome problems associated with the depuration of wastewaters and gas streams.

Environmental Benefits

Thus, the environment is improved in two ways:

• Hazardous waste recovery
• Effluents depuration

Z-ONA4LIFE considers salt slag as a secondary raw material and creates an opportunity for recovering waste from other industries.

Objectives

Z-ONA4LIFE aims to close the loop between:

1. Waste generation
2. Its treatment
3. Development of valuable materials
4. Their future market

Different environmental and economic factors are considered to select salt slag as raw material, including:

• Aluminium industry world relevance
• Huge salt slag volume
• Its hazardousness
• High disposal cost
• Scarce recovery processes feasible on an industrial scale

Product Selection

Zeolite is selected as the optimal product for the valorisation of salt slag due to its wide application in many industrial sectors. The use of Z-ONA is also foreseen when depurating gas streams and wastewater (leachate, livestock, and mining wastewaters) in demonstration plants and real scenarios.

Near Zero-Waste Process

Finally, to reach a near zero-waste process, enhanced compost will be produced from spent zeolites.

Expected Results

The expected results of the project include:

• Recycle 145t of salt slag & 95t of silica waste
• Produce 220t of zeolite
• Depurate at least 118m³ of landfill leachate
• Use at least 100t of zeolite for livestock/mining effluents & gas flow
• Produce 25t of enhanced compost
• Produce 120t of organic soil
• Develop international business & replication plans