Les Moulins du Littoral

The company Les Moulins du Littoral in Dunkirk uses its roller press to process converter steel slag produced by the ArcelorMittal Dunkirk plant, which is selected to be ground to the fineness specified by French Standard NFU 44001 – 09/2017 – applicable throughout France.

This ground converter slag then becomes a Class IV Type 9 steelworks calcium soil improver, as defined in the standard for agricultural use.

Users can spread it on cultivated land and grassland, thereby not only regulating soil acidity but also providing trace elements such as P₂O₅, MgO, Zn, Cu, Mo and Se. To do so, they will need to be equipped with spreaders or contact service providers to organize the spreading.

Customers can arrange transport to their storage facilities or direct consumption sites; LML can assist with this organization to deliver volumes of at least 100 tons for bulk soil conditioner or a lorry load of 47 big bags, each weighing 600 kg, for flatbed lorries.

Quotations are provided on request for the minimum quantities described above.

On this website, you will find detailed information about this steelmaking calcium additive and detailed access details for the LML facility.

Efficacy of steelmaking calcium amendment: converter steelworks slag produced at LML Dunkerque in accordance with standard NFU 44001

COMPARATIVE STUDIES OF CALCIUM APPLICATIONS IN SOILS

Calcium can be added from various sources, all grouped under the term ‘calcium amendment’. Its addition enables the soil to maintain effective yields and continue to improve these yields.

The calcium released by converter steelworks slag plays a significant role in maintaining the soil’s cation exchange capacity whilst maintaining a basic pH.

Maintaining this environment through the controlled application of calcium amendments promotes bacterial growth by sustaining favorable conditions largely linked to soil pH; however, these amendments also act at various levels, as described below:

- Calcium improves soil structure; consequently, its presence allows for better root development and facilitates water movement. This soil structure significantly reduces leaching and minimizes the loss of arable soil during heavy downpours, for example,

- Calcium also dissolves gradually and acts chemically, thereby creating pH conditions that facilitate the transfer of fertilizers to the plant; this is further aided by the root system, which develops more effectively under its influence.

- CEC / ‘Cation Exchange Capacity’ / helps to increase ion exchange when fertilizers are present in ionic form in the soil, provided that a stable, neutral pH is maintained through pH regulation achieved by the presence of lime in converter steelworks slag.

Calcium is a key element whose levels in the soil are constantly fluctuating due to the combined effects of leaching, fertilizer applications and other soil amendments; soil analyses enable you to continuously determine your soil’s nutrient requirements.

Calcium-based soil improvers come in a wide variety; the use of steelworks-derived calcium-based soil improvers provide not only calcium but also beneficial elements such as phosphorus, silica, magnesium oxide, zinc, copper and molybdenum.

Example: P₂O₅ content in steel industry calcium soil amendments: between 10 and 20 kg per ton.

Numerous field trials assessing the agronomic performance of steel industry calcium soil amendments have demonstrated their effectiveness. These trials and long-term monitoring over several years have enabled comparisons of the efficacy of the products used on the same soil:

- Improvement in soil water infiltration capacity through liming of loamy soil,

- Impact of silicate and non-silicate liming materials on water-extractable calcium and silicon levels in the soil – monitored over 15 years,

- Effects of liming agents on maize crops: long-term experiment (19 years of monitoring),

- Mobilization of soil phosphates through the application of liming agents: monitoring the effectiveness of phosphate fertilization and phosphate fixation,

- Phosphate mobilization when using steel industry calcium amendments,

- Measurement of soluble silica in relation to different applications in cultivated soils: comparison of the effect of steel industry calcium amendments with applications from various sources: biolit, ground basalt, lime residues, etc.,

- Measurement of calcium silicate solubility as a function of the type of input.

You will find all the data detailing the observations listed above in this section.

A subsidiary of ArcelorMittal France, L.M.L (Les Moulins du Littoral) is a dynamic small company specialised in the grinding of steel slag from the ArcelorMittal plant in Dunkirk.

By processing slag, we put the circular economy into practice and, every day, repurpose steel slag for high-value applications such as agriculture (agricultural spreading), construction (soil treatment using hydraulic road binders prior to the construction of roads, platforms, etc.) and waste stabilisation. This contributes all the more to environmental protection as the main components of the finished products leaving LML have a very low carbon footprint.

All of this activity promotes sustainability and reduces our clients’ environmental impact.