MINIMISATION/ELIMINATION PRODUCED IN THE MANUFACTURE OF ALUMINIUM SULPHATE

Company and project background

DIMENSA, DAMIÁN DÍAZ SÁNCHEZ, S.L. is a medium-sized company founded in 2000 dedicated to the manufacture of inorganic salts (aluminium sulphate) for use in the treatment of drinking water, wastewater and industrial water, as well as the wholesale marketing of basic inorganic chemical products in different sectors.
The project that has been carried out is the MINIMISATION/ELIMINATION OF WASTE produced in the manufacture of aluminium sulphate, whose final destination was the landfill site for non-hazardous waste. In other words, the aim has been to eliminate the linear model of management of our main waste by applying a circular strategy of reduction and reuse within the production process.

What motivated you to make your business more circular?

As indicated, the company’s management, within the framework of its Environmental Management System implemented in 2007 in accordance with the UNE ISO 14001 standard, has been promoting the continuous improvement of its environmental performance through actions aimed at reducing its environmental impact and optimising the resources used and its processes. However, the drive for change has also been reinforced by new policies promoted by the European Union on the disposal of industrial waste in landfills, which have significantly increased the associated fees and imposed restrictions on the characteristics and forms of disposal. These measures suggest that this option will become increasingly limited in the near future, making this the ideal time to commit to waste prevention and reuse within a circular management model.

Implementation Process

What were the objectives of your project?

We set ourselves two goals:
•
The first was to REDUCE the amount of waste produced by 60% by improving the efficiency of the reaction. From around 135 tonnes generated per year, we wanted to reduce this to 80 tonnes, which in relative terms means that from 9 tonnes of waste produced per tonne of raw material, we wanted to move to 5.4 tonnes of waste per tonne of raw material.
•
The second was to REUSE the rest of the waste generated, i.e. 40% of that produced in the reference year within the process and on a continuous basis, which has led to its elimination.

What activities did you carry out as part of your project?

The activities carried out for each of the two proposed goals were planned and followed a similar sequence. First, the University of Córdoba conducted preliminary laboratory-scale studies. Based on the results, a study was conducted on the equipment and/or adaptations needed for subsequent application in the process. After implementing the necessary modifications, where necessary, process-scale tests were carried out.

What feedback did you receive from stakeholders (customers, suppliers etc.)?

To date, no feedback has been received from customers, as the benefits of not managing waste and greater efficiency in the use of raw materials have not yet been reflected in the price of the product. However, it is expected that these improvements will enable more competitive prices to be offered in the future.

Impact & Outcomes

What are the main results and outcomes of the project for your company?

The main results of the project from an environmental point of view have been:
o An effective 60% reduction in manufacturing waste generated compared to 2023, which has led to a more efficient use of raw materials, from 91% in 2023 to 96.4% in June–July 2025.
From an economic sustainability perspective, the project has also been a significant achievement
o The effective 60% reduction in the amount of waste has led to a reduction in waste management costs of €28,484 per year, as 81.6 tonnes of waste will no longer need to be managed.

Did you detect a positive impact of circular transition for your company and for the environment?

The project developed has had a clearly positive impact on the company’s circular transition, satisfactorily meeting the expectations initially set. This has been possible thanks to the fact that the project has enabled the establishment of a process that replaces the linear management model for our main waste (which represents 90.6% of the total waste generated) with an integrated system that minimises and reuses this waste within the production process itself. This change represents a very significant step towards a circular economy model in the company’s internal management.

Which changes have you already implemented?

The changes that have been implemented and are now fully operational have improved the efficiency of the aluminium sulphate production reaction by modifying the quantities of raw materials added, which has led to a significant reduction in manufacturing waste and more efficient consumption of raw materials.

Leassons learned

What key lessons did you learn regarding circular innovation?

One of the main lessons learned is that circular innovation is perfectly applicable even in established industrial processes such as ours, provided that they are approached with an open mind to change. Furthermore, I have found that applying circularity principles is particularly beneficial for the company, as it leads to a direct improvement in process efficiency. In our case, we have increased the percentage of use of our raw material, a scarce and costly resource, and we have reduced waste generation, thus decreasing the volume sent to landfill, an impact that is always desirable to minimise.

Did you encounter any challenges?

The human factor for integrating changes into the work routine is not always easy, especially when it comes to initial tests whose benefits are not yet evident. Workload and operational pressure can generate resistance or limit staff involvement.

If you could do your project again, what would you do differently?

If I could do the project again, I would spend time at the beginning promoting and providing detailed information about the planning, objectives and expected benefits to everyone involved: department heads, technicians and operators. I believe that raising awareness in this way would have made it easier to get staff involved from the outset.

Future plans & Recommendations

What are your next steps towards circular transition? (Which partners would you like to team up with/collaborate)?

Based on the positive results obtained, we have established a series of actions to expand and consolidate the achievements made:
In relation to waste reduction (goal 1): Once the measuring equipment for continuous monitoring of the reaction temperature variable and the stirring equipment have been installed, we will re-analyse the process data and carry out new tests to achieve the most optimal conditions. The aim is to continue improving process efficiency and limiting the conditions that favour waste formation.
In relation to waste reuse (goal 2), we will work on adapting the facilities to facilitate the work and standardising both the washing process and the introduction of waste. In addition, the waste will be monitored to assess the influence of its continuous introduction on the degree of impurity concentration and on the properties of the final product.

Is there any advice you would give to other SMEs looking to implement a circular project?

My advice to SMEs that want to launch a circular project is to study their processes carefully and prioritise a specific environmental aspect: the one with the greatest impact or the one that is easiest to address. It is not possible to transform the entire company, so it is important to start with a limited and realistic goal.
Once you have determined the aspect you want to innovate and unless you have a research or innovation team, I would seek external technical support to help staff coordinate and facilitate decision-making.

How can policymakers or financial institutions better support businesses in adopting circular practices?

Policy makers and financial institutions can better support businesses in adopting circular practices by offering more accessible aid that is tailored to the operational reality of SMEs. Often, programmes exist, but they are complex and require the completion of lengthy questionnaires that are unmanageable for the staff of many SMEs.