LAARMANN Group BV has developed an efficient system for sample preparation in the steel industry. With this system less material is needed to be send out for external analysis. This provides a mayor saving in material costs. Additionally the system simplifies the preparation process in a way that the amount of samples can be increased resulting in a quality improved of the production process.
The determination of the quality from the purchased or produced goods is depending on the way a representative sample is taken and the preparation of this sample. In-line sampling is crucial to monitor and control the production process. Incorrect taken samples or samples processed in an incorrect way will lead to false analyses, resulting in goods being approved (false positive) or declined (false negative) wrongly. In the last nine years LAARMANN Group BV has specialised itself in advising, designing and building solutions for representative sampling and processing of bulk materials.
LAARMANN Group B.V. strongly encourages (bulk processing) companies to implement their own sampling process instead of outsourcing it. Outsourcing this process creates many expenses, just think about the amounts of product that are lost during the process.
To ensure that an external company has a representative amount of material the companies need to send dozens of kilograms, where for the actual chemical analysis they require only a few hundred grams. Apart from the questions whether the external company produces a representative sub-sample, the companies never see the remaining material (the reject) again. The question is what happens with this, often, costly material.
In this way, especially when there are big quantities of precious material, it is most preferred that companies process their own samples. With a good sample preparation process, the amount of sample that needs to be send for analysis can be reduced from dozens of kilograms to a few hundred grams. Processing the samples in house will make it possible to take multiple samples to determine the quality of the bulk even better. Companies who successful implement this system not only reduce their material cost but also their transport cost.
LAARMANN Group B.V. developed an efficient and reliable system for sample processing of raw materials. In this specific case we look at the production of Stainless steel. To create stainless steel you add precise amounts of Chrome, Nickel, Titanium and Molybdenum to Iron. These materials, who represent high value, are bought as Ferroalloys.
Correct determination of the metal content within these alloys is crucial when producing stainless steel. A shortage of certain elements will lead to an inferior quality of stainless steel, while an excess will only increase the costs of the production.
To determine the qualities of the Ferroalloys the pieces of alloy (60-70 mm) are sampled and then reduced. The steel company used to reduce the 25 kg of materials using a jaw crusher (reduction down to 10 mm). After the primary crushing the operator needed to grab the material from underneath the machine and put it in a rolls crusher. Here the product was further reduced to grit (< 2mm). The sample was send over to an external laboratory for analyses.
Push off a button
The installation of LAARMANN Group BV has simplified the size reduction process for this steel company to a mere push of a button. Now since there is no more need for the operator to lift any heavy materials or perform multiple actions the process is more efficient, resulting in more samples and an overall higher quality.
The operator puts 25 kilograms of material in the inlet funnel and starts the process at the central control box. A vibratory feeder underneath the inlet funnel evenly feeds the bucket elevator. The bucket elevator lifts the material and feeds the jaw crusher (type LMFC250) which reduces the material to < 2mm. The grit material goes, using a flexible connection, to a rotary sample divider which divides the sample in ten equal parts of 2,5 kilograms (sub samples).
The alloys have a density between 3 and 8 kg/liter, giving a partial sample volume of 500 to 800 ml. This sample will be pulverised in a ring mill (type LM2000) to reach the desired end finesses of 125 micron.
The external lab needs 12 to 15 grams of this product to make it into a tablet that can be analysed with an XRF-machine (X-ray fluorescence).
The funnel above the LMFC250 jaw crusher can be moved aside so that the installation can handle smaller quantities of material without contamination of the bucket elevator. Sliding the funnel aside will make the crusher easy accessible for cleaning.
The bucket elevator has multiple hatches which can be opened for cleaning the buckets. However cleaning the bucket elevator will not be needed on a regular bases, due to the fact that the material entering the bucket elevator is quit big, there will not be a lot of dust.
The integrated rotary sample divider is mobile so it also can be used as a stand-alone machine in the lab. Thanks to the compact design of this installation the space of the laboratory, which often don’t have much space to begin with, is used optimally.