the conference is now starting all attendees can now hear you good morning my name is sue heartless Euler and I’m the director of operations at Osaka micron powder systems I would like to welcome all of you to our webinar titled wet and dry milling before we get started with our presentation I’d like to give you a brief introduction to who we are hosokawa is one of the largest powder processing companies with over half a billion in revenue and 1,500 employees throughout the world we have a presence in all five continents and twelve centers spread across the globe our primary objective is to provide solutions in the areas of size reduction classification mixing drawing and containment host Akala micron powder systems located in Summit New Jersey is the unit responsible for north american market with a complete engineering staff test center and service group our aim is to provide a one-stop solution to our customers I would like to remind everybody that you know if you have questions please type them in in the question-and-answer section of it and what we will try to do is at the end of the presentation we will try to answer as much as we can with that I would like to turn it over to my colleague dr Stein from our sister company in Germany Alpine to start the presentation dr stein if the gentlemen good morning from Germany processing at Aqaba I’ve been in in Germany we are located in the south of the country and with our 100 years 10 years old tradition we are one of the oldest we are the eldest unit in the Xhosa cava group there are 560 employees working in the two divisions powder and particle processing and blow end in the blown film division let’s now start with the today’s topic which is wet and dry medium milling and first of all I will give you an and it’s away over the topics of my talk I will try to get the next slide here I think it will take a second from the u.s. to Germany and back sorry for this delay ok we have it so during my talk I will speak about first of all the fundamentals of medium milling to give you some theoretical background I’ve also talked about the basic types of the mill of the medium use then I go into the technology of dry and wet medium Mills will give you some informations about possible applications and the plant technology and finally some informations about an interesting field which is submicron grinding with wet and dry medium Mills before I enter into the technology of the mute I have a survey on all these on all the main established types of Mills on the top of this graph you can see in green color the dry Mills and on the bottom in orange color the wet Mills what you also can see is that all these mill types are covering a range of about nine decades of particle size reaching down from one meter ox to about nanometers particles which can be ground nowadays the fundamentals of wet milling this is easy to to explain and on the next slide you can see a very simple mill it’s a very early model about 20,000 years old but it’s a very very suitable machine to explain the mechanism of media branding you can see here the basic parts of a media mill which is the grinding medium it is one only in this mill and we have a part of the mill the kind of support and in between there is the powder which we want to grind to explain the basic rounding mechanisms which can occur in the radium milk if you take this stone in your hand and you knock on the support you create a kind of impact on the particles you can also take the stone and roll it with pressure and you have a pressure in precious dress on the particles or you rub the stone on the

support and then you get a shear stress in of the party but these are the basic types of grinding mechanisms which grinding media can bring over to particles and this is the same in modern Mills I think the next slide will show what the difference is and what the similarities are this is a modern grinding that we have not only one grinding stone we have lots of grinding beads inside and but the same things will happen we have balls ball contacts which create an impact on the particles we can roll the balls and create pressure or we can shear the particles between two passing grinding beads so this is so far the same as in the old mill however in the old mill you can take the stone and decide by yourself which grinding mechanism you to have this is actually not possible in a modern grinding mill deep because you have thousands or millions of grinding beads inside so there will always be a mixture of oneis grinding mechanisms in the in the mill there is a certain chance to influence that by setting the parameters of the mill like the like the rotor speed or the filling ratio of grinding beads or the material or the size of the grinding beads but you can only create a tendency to get more impact or two more shear on the on the particles but you cannot decide to make a finger she is reading in in a moment with such a high number of grinding beat let’s now come to the mills themself this light is showing you a survey on this on the different types of medium mills which actually are existing first of all we have a tumbling bonemeal which is the rotating drum in horizontal axis and the grinding beads are accelerated by the rotation of the drum and falling back and grinding energy input is done by the gravity which is affecting on the grinding beat if you need more energy and put into the mill you cannot count on the gravity you have to look for external forces which you can bring into the grinding media and this can be done in different ways one is the agitated media meal with the rotor rotor inside which is rotating and bringing the motion into the grinding media feelings can also do this by a planetary mill which has a certain other rotation of the mill and then the grinding chambers themselves and you can simulate a tumbling ball mill grinding under centrifugal forces other types of music vibration mills but the grinding body is is moving with a high frequency to transfer the energy into the grinding beats or centrifugal music doing basically the same but with a lower frequency to create a kind of a rolling grinding media feeling inside for my presentation I pick out two types of the mills which is the tumbling ball mill running with the gravity forces and the agitated bombers which we can apply for dry and wet medium early I start the technology first with dry Mania mills this photo is showing a tumbling ball mill very classic type operated in a continuous way we have here a machine with a drum diameter of about two and a half meters and a length of six meters which is a normal production scale machine for ultra fine minerals grinding you can see the drum a rotating drum here the drive unit and the bearings on both sides the material fed into the milk from this side here and leaving the machine in this case on on the bottom on this side of the mill these mills are usually operated continuously but not as a single meal with one path through the mill which is definitely not sufficient for a for a very fine grinding we always have a system with a grinding circuit comprising the mill and the classifiers I can show you on this flow sheet how this can work this is a typical form the classifier plant which we are always applying in the minerals industry the feed material comes from a silo here and is charged into the mill by a dosing unit and is passing through the mill in this direction here the mill is containing grinding beads made of steel or ceramic and the size of typical size range of the beads is 10 to 60 millimeters after passing the mill the material is being discharged and conveyed to the classify in this case we have a typical arrangement with two classifiers so we can split the material to a course a

classifier which making one end product or to a very fine classifier to make a second product which is collected in the filter and so this is a plant that can produce in parallel to different products the coarse fractions from the classifiers are being recycled to the mill and going back into the circuit again alternatively to the tumbling formula we can also choose agitated media mills to have the chance to bring a higher energy into the grinding chamber and this is a type of mill which which we are supplying it is called ATR it’s a vertical cylindrical grinding body and has a vertical shaft with rotating elements and these this mill is filled with the grinding beads up to the top and the rotor is in slow motion slow motion of about 2 to 3 meters per second typical mill volumes are in the range of a thousand or 2,000 liters with power installed reaching up to 315 kilowatts so the power input which we can create with such a mill over 180 kilowatt per cubic meter mill volume is significantly higher than the tumbling born mill hat these milks also are operated in in a closed circuit system with classifiers I can show you this on the on the flow sheet in the center you can see the medium mill the grinding beads and the product is fed from the top into the mill and both beads and product is passing through the mill being ground and then discharged by a conveyer screw out out from the mill beads and product are separated on a vibrating screen the beads will be collected in a sir in a special hopper and being researched into the mill by a bucket elevator the product parting the screen is going on into a classifier and the fine product collected in a filter is the end product of the plant and the course traction is being recycled we are the back of the elevator into the mill again so this is also a closed grinding circuit with mill and classifier to create such a ultra fine grinding system it is it is important to have a meal which has a high energy input and can be operated with no grinding media however it is very important also to have appropriate classifier for the typical and products you want to obtain with this plant and this slide is showing you a selection of of classifiers which we can offer together with such plans for the grinding circuit on the left side you see a circuit a classifier we call it event of Plex which is dedicated to make classifications in the range of 30 to 300 micron so it is more on the coarse range of the often of the products we have a spiral flow classifier ASP strata flex which can do a little finer it is designed for high capacities and low pressure lots of very economic lattice occation and we have very fine classifiers which is the ATP to look like classifier or the TTC to Abu twin with a special wheel geometry which can go down to five or even two micron operation cut some details of the classified can be seen in the in the next slide on the left side you see the to apply classifier and a special arrangement with with multi with multiple wheels so in this case it is six classifier built in one classifier housing and with this classifier it is possible to make very fine separations with high capacities this can even be improved with a with a new type of wheel widget which we call the ng new generation wheels it has a special blade geometry it is creating a forced vortex separation inside and this classifier wheel is able to go down with cut sizes to about three micron or in the TTC wheel which we’ll see below down to about two micron separation the result of such a such a plant can be seen in the following graph Green is the feed material orange is a result of a born mill a classifier system and the yellow

curve is showing product which is coming from the vertical media mill ATR what you can see obviously is that we reach the expected I call it grinding limit of about 1 micron d50 and even with a high intensity mill the vertical medium mu we cannot go significantly finer than the bone so it seems there is a limit of grinding and I will come to come back to this problem later again when I speak about sterilization of the particles but first let’s go to the wet grinding on on the top of this slide you can see five different models of what agitated medium is this is the basic types which are existing on the market we have vertical Mills with with a vertical axis in an open and closed design we have horizontal Mills with disk agitators which with pin agitators and we have also annular gap Mills which do not have grinding tools they they just have a small gap to Electric accelerate the grinding beat are we talking about – Mills which which are Tina’s offering in his product line which is at the universal mill or horizontal type Alpena ahm and we have the vertical mill ANR which is an open type with vertical shaft the aim are on the next slide the machine can be seen is a machine which we especially applied for calcium carbonate grinding for the paper industry the paper industry is consuming lots of calcium carbonate slurries and high concentration high finest to fill and to coat the pigment of the paper and so these mills are designed in big scales only we have mills up to nine thousand liters volume with one megawatt drive and this our typical sizes for the paper industry which is consuming this big amount of slurry the mill itself has a cylindrical grinding chamber here with a vertical shaft inside the shaft as agitating element was wear protection and the mill is completely filled with grinding media about one millimeter size on the next slide you can see an example for a for a plant aster and the results of products which we can produce with this plant you can see on there on the photograph that this is plant with six mils each has 450 kilowatt Drive and 5000 litres of volume we see 3 3 mils in a line and 2 lines in parallel but this plant can be flexibly connected to realize to to make a single a double or triple path grinding depending on the finest you want to obtain and the product can be seen on the on the graph on the left side we have we have ground calcium carbonate slurry with a solid concentration between 75 and 78 percent the feed particle size is 325 mesh coming from a from maybe from a table roller mill and is pre-mixed in a slurry than fine ground to the required finest or quality and finally may be classified is necessary with screens or centrifuge and finally stored into into big tanks to be supplied directly into the paper factory you see the typical fineness is required this was a little bit too fast for this slide you see the typical finest for the paper industry it is reaching from 60 to 80 percent below 2 micron in the particle size distribution for typical filler materials and from 90 to 99 percent below 2 micron for for top coating pigments for the paper ii mill i want to talk about is a very very universal mirror which you can nearly apply for any product which would you want to grind in a slurve it is the horizontal media mill ahm and this mill is very flexible in in the size we can we have product line reaching from a very small machine for speak oleg with 7 milliliters Morris grinding volume for research applications you can use it for about half a gram or 1 gram of material to grind particularly for the pharmaceutical industry then the line is reaching up parking a lab mill some pilot scales to going up to production machines which can have a thousand

litres volume and 350 king over you can see the smallest and the biggest machine here on these photos the match box will give an imagination of the size we talked about on the next slide you can see some technical features of this mill and first of all you can see a dynamic bead separator on on the rotor and a very fine screen which is separating the grinding beans from the slurry when when leaving the machine but this has a direct dynamic hair relief so that means the machine is suitable to run grinding beads down to a very small size which are necessary if you want to make Reiner not nano grinding the screen can be exchanged and serviced very easily the machine can be in the mill can be opened without emptying the grinding beads so this is a sing-off a few minutes only to make a service on the screen another feature is the flexible wear protection system you can see here’s some examples but this is a mill which is completely lined with Taccone iam dioxide ceramics and some wear parts made of polyurethane of steel and of another type of ceramic so the machine is the kid system and you can can change the rotor and the stator parts made from these materials polyurethane for for water-based flurries some metal materials different ceramic materials and all even even materials are applicable to this machine following slides I can show you some applications of the horizontal medium mute this is an example of small plant which can grind high-quality it’s a chromium dioxide for electronic applications you see that we are making a product with a d50 around 500 nanometers which is a very typical size for for standard media grinding the plant itself is comprising two meals you can operate them in in parallel for high capacities or in a serial connection and for high fineness it’s even possible to put different grinding media sides into the machine to optimum to optimize the grinding for very fine particle size the next slide is showing a small plant for for titanium dioxide processing and you also can see that that we reaching down to about 300 nanometers particle size but actually this is not a real grinding this is a dispersion of agglomerate titanium dioxide is this particle size distribution of the only agglomerated primary particles and by circuit grinding we can obtain the primary particle size of this product a special application is shown in the next slide which is the photos showing 200h and model which is a production machine in GMP design which is applied for for the wet grinding of active pharmaceutical ingredients you see all the machine is made of stainless steel which with cleaning systems and monoblock design so it is it is applied for the special requirement of cleaning and that link of the pharmaceutical industry and on this on the graph here you can see an example for for a grinding of an of an active ingredient which is starting on a maybe 10 micron size and reaching up finally to a nano size of about 150 nano meter and this particle sizes are very important for an soluble active ingredients which are dispersed in in a liquid to increase the bioavailability of this of these ingredients finally on the next slide we have an application for real nano grinding this is an example to grind aluminium oxide in water and we have used 9 tah and plant which is a complete we call it a plug-and-play system everything which which is need it is integrated in this in this rolling box here we we have a pump an agitator with a cooling tank pressure liquid system for a photo for the shaft seal and the mill itself which is a 1 liter meal for lab applications and we can see here that we have made real grinding of aluminium oxide particles reaching out to a particle size of finally 50 nanometers d50 but to be honest it is not just grinding it is it is a special recipe of the slurry which is containing stabilizers surfactants to to make this agglomeration stabilization of the fine

particles I also come back to this topic of a few slides later but before I speak about stabilizers I want to give some some informations about the grinding media because it is not the mill not the medium there who is making the grinding it is actually the grinding beads who have the contact to the particles and the grinding media are the tool to grind so it is extremely important to choose the grinding media in a right manner and I have listed here some properties some some criteria for the grinding media first of all we have to select the right size grinding media for for agitated media mills are available from 15 micron to 3 millimeter size approximately maybe 10 for special meals and we have to look first at the free particle size to be sure that the grinding Maivia are not too small to obtain the grinding effect on the big feed material and we also have to look on the only require and fineness and for very fine materials we need a high number of very small grinding media and so it’s important to find the right grinding media besides respect to these particles as you see we also have properties like hardness strengtheneth and so on which which have influence on the selection of the beads and finally we have to look on the contamination because medium milling always creates abrasion which is going from the mill into the product this contaminates the product and is reducing the lifetime of the mill and the grinding media and so it’s also very important to choose the right material of the beads which can be metal material glass different ceramic materials of plastic materials to optimize the performance of our mill you can purchase also very specified grinding media which are called power beads and we supply them together with our mill just to imagine the importance of the media size I’ve prepared this slide here it’s showing two grinding beads with a diameter of one millimeter which which is this blue curve here is reaching up to the top of your room and in between you can see in red color here a 2 micron particle and you can imagine that it’s not too difficult to hit this particle to crush it within two weeks but if you decrease the particle size to maybe some some a few hundred nanometers who see this small black dot see and you can imagine how difficult it comes up to hit these particles to make it to make an crushing of the particles life can can show impressing Lee how important it is to choose the right size of grinding beads and in this case for such small particles is important to decrease the size of the grinding beads and increase the number of the beads to be sure that all these small particles can be crushed during the grinding and the two figures here the stress intensity and the stress number could appear could you please switch make one one second are the terminating the grinding effective stress intensity is more or less the kinetic energy of the grinding beads and has just to be sufficient to crush the particle not too much and not too late and the stress number is indicating the the number of stress events during a grinding which is being affected on a particle and for very small nano particles or sub micron particle is very important to have a high stress number and finally the grinding energy is being calculated from the product of stress anger and stress intensity this is a means to calculate an optimizer grinding media mill yeah on the next slide I show you an another let’s call it a problem of grinding of medium mills which is departing the residence time distribution continuously operated mill with product is coming in on one side passing through here and leaving by the screen on the other side has not a motion like it’s characterized by the red arrow here it is not a straight flow through the mill there is a heavy turbulence like the yellow arrows show here so some of the particles are staying a very long time the mill others are passing through very quickly which is resulting in a white residence time distribution and accordingly also a white particle size distribution and it does not help a lot to change the geometry of the mill it can have a little effect but not secure significantly but another means to influence the particle size distribution is it’s the mode of operation of the

mills which is shown on the next slide with the yellow mill this is the single path operation which I have shown in the slide before resulting in a very white particle size distribution if we increase the flurry flow through the mill the influence of the turbulence is decreasing and we get a smaller path deeper particle size distribution as you can see for this blue arrangement where we put three meals in a serial connection this is extremely interesting for us because we are selling meals and if you want to make 20 passes here we can sell 20 meals for that this becomes very complicated so there are two other Modi – to operate the Mills which are easier to handle and cheaper investment the red mill is characterizing one big mill again and we put the two tanks around the mill and running the material from one tank through the mill and then going back through the mill again back to the first tank so this is a kind of Jojo grinding and we repeat this as often as we want three times ten times twenty times if needed and the result is characterized by the red curve here very steep particle size distribution however this operation is a little bit difficult to control with valves and liquid level sensors and so on and some some people make life easier and make a simple circuit grinding they take the same wheel size and run the materials just in with one tank and one agitator the resulting curve is the green one which is still a steep nodding size distribution not that good as the red one is first but sufficiently the defect comes from the mixing statistics of the tank which has an influence on the residence time of the no.2 but this is a very easy process which can be applied for many many production plants yeah so far the milling technology I would like now to talk about this supposed grinding limit which which I have have minded some slides before the words dry milling and the dry milling example which ended up around 1 micron and the reasons for that is that the particles the finer they come the the bigger are the forces which which try to attract the particles to each other and to form a global rate of the party which you can see this here the particles are stressed by the grinding bolts reaching a certain fineness and immediately agglomerating so the grinding beads have to destroy the agglomerates again against the attracting forces and then a real separation occurs and then again agglomeration so there is no grinding progress anymore because there is no crushing of the particles it is always a real operation by the attracting forces the other thing that can happen this is valid for dry and wet grinding for dry grinding an additional effect is occur occurs that the grinding media are coated with sticking particles and forming a big layer around this grinding needs and so the the grinding forces between the particles are blocked and not a real efficient grinding can can occur anymore but there the error means to do something against it so we have to try to influence the particle interactions we try to influence the surface properties of the particles which is shown in the in the next slide and if we if we put some additives on grinding aid into the powder which influences the charges on the surface or other things I showed it on the next slide then it is possible to shift the particle size distribution away from the from the 1 micron grinding limit into the sub micron range you can see some examples here of different additives and also an additive mixtures which we have done in a lab machine and a small planetary mill and you see that nearly all of the particles are now in the submicron range with a 50 average particle size reaching down to about 300 nanometers so this is still R&D work which we are doing it is not state-of-the-art there are some industrial processes of for example calcium carbonate grinding where we already used some grinding aids to influence the agglomeration behavior of the powder but we cannot obtain yet such fine particle size distributions in a industrial dry milling process this is different to wet milling we are many steps further in wet milling and on the

next slide I can show you the mechanisms of stabilization which we can use and we’re moving there are three different mechanisms which which we which we find one is the electrostatic stabilization this is creating a charged layer around the particles and if two particles have the same charge here forces are blocked and the particles cannot agglomerate anymore we can alternatively do a stearic stabilization where we put some long-chain molecules on the surface of the particles and the long chains keep just maybe we call it mechanically the particles apart from each other so they can also not not approach each other because they are blocked by the long chains of the additive molecules it’s also possible to combine electrostatic asterick stabilization and get electro stereo stabilization where we have some molecules with charged groups at the end which and the charges additionally support to keep the distance between these particles and in liquid slurries it is very easy to bring in such additives for example if you have a polar liquid you can do the stabilization electrostatically just as it is shown here in this graph this is this is our curve for three different materials and examples and showing the value of theta potential which describes the charge layer around the particles and the pH value of the slurry you can see different materials have different behavior if you look at this green curve it is obvious that we can stabilize the particles in the in the in the acidic range of the slurry and pH values from zero to six we’ve over five we have significant seater potential which affects like this here and keeps the particle stems stable in the slurry if we go down here to the to the zero zero charge point we come into the field where we have agglomeration the charges disappear and the particles will stick together the red curve shows a different behavior in this case we would put some some base into the slurry to make an acrostic pH value there we have a I think the potential to keep it step stable if we have products which do not react on the pH where you like the yellow curve shows then we cannot make an electrostatic a stabilization we have to choose one of the other methods yeah and this is the trick to come to nanoparticles and with this example I can show how successful and how easy this can be this is a standard grinding system with a horizontal edge and mill just as a circuit grinding with pump tank and ant a mill and we have ground an inorganic pigment which finally reached down to a average particle size of 19 nanometers just by electrostatic stabilization by shifting the pH value to the appropriate eater potential yeah and this brings me to conclusion we can identify three important tools to obtain which are fine milling that means bringing a medium milling into the into the submicron range or even into the Nano range so this is valid for dry and wet grinding we can we find out that medium Mills dry or wet are the suitable machines to bring in the certain the necessary energy and impact events to get a very fine or ultra fine milling we have to choose the right media especially the the media size is very important and for nano grinding we go down to 50 micron or 100 micron beads to make this economical in a short time we also need high performance material for the grounding media to avoid contamination of the of the product and finally the most important we have to choose the right additives to influence the surface activity surface interactions of the particles to avoid the agglomeration and to stabilize the fine ground context yeah in the next slide edge I can show you some field of application it’s just gives you a survey of the versatile applications for medium Mills for Woodruff and grinding and you can see nearly any industry can have a benefit in this yeah and this is the end of my

presentation I just feel free to show you some some exhibitions which which come up in then in the next month and we’re how the Carver is participating we have two exhibitions in Germany one one is the politest which is one of the most important European exhibitions about powder processing and in September in October in Nuremberg Germany we have next year in May they are FEMA in Frankfurt and there are some some other exhibitions and events in in the United States which which are coming up soon and September up to 2 November and exhibition in March you can see well thank you very much dr. Stein this this basically concludes our presentation and now we’re at the question answer session and as I mentioned earlier on if you can submit your questions via writing and into the question answer section submitting to us in the next five to ten minutes we’ll try to answer as much as we can and the ones that we do not cover here we will take care of it v Utley in terms of providing you an answer after this webinar is concluded calling you or send us an answer to your question is one of the questions that that showed up dr. Stein is is basically what’s the energy consumption for the different wet ground G cGCC qualities yeah it depends on the finest we want to have and this is starting on the the low-end for for record filler material with 60% below 2 micron the energy consumption is around 35 kilowatt hours per ton related to dry solids and it is reaching up for the D 99 for the 99% below 2 micron material which is around 200 kilowatt hours per tonne and you know what I guess I’m all at the same time transferring some of the questions to dr. Stein for for him to kind of pick through the ones that you know would I guess have the most generic appeal to so you know one question I have here dr. Stein as you look through the rest of them is is a continuous dosing of additives needed during the wet Nano milling process Korea didn’t get that could you repeat sure his is a continuous dosing of additives needed during a wet nano milling process it is yes we have always to control a constant pH value or a constant conductivity in the material and we have to keep the optimum conditions for the stabilization so it is needed to reduce the the additives constantly and it’s needed to control some properties of the slurry to have to have an image what what we have to do and this can be done by by measuring viscosity by measuring conductivity or pH value or even measuring the particle size directly in light next question I have is can any of your equipment be used to make below under nanometer API it’s a very generic question I guess so you know as far as you know you have shown that you have done a d50 down to 19 nanometers maybe this question might need to be a little bit more specific in terms of being able to answer it basically basically we can say that it’s possible to reach this particle size but we have carefully to look on the suitable additives here and this needs some some basic considerations about the chemical activity of additives and and and the grinding material and usually it needs some testing to find the optimum conditions for this grunting intensifies

answer by process yes it does the examples I have shown with some mixtures of additives this is this is containing materials molecules for theory stabilization or electrostatic stabilization in dry powders it is usually not possible just to put a charge layer around the particles because the polar medium around the polar liquid is missing so in dry milling it is usually a spherical stabilization on six – less than fifty 50 micron size I have to look at our testifies I cannot answer this question at the moment but I can do it later when I have checked the test files and give some detailed informations on this product okay maybe just keeping it out of generically you know in terms of polymers have we done any testing or on polymers basically in the would say some micron range I’m not sure about whether we were successful with polymers yet okay some sort of polymers which can be ground under certain conditions but it’s very difficult to do that okay I have one other question here I guess milling system how would you drive the wet milled material to maintain particle size for the dry products it is usually not possible to maintain the particle size for the dry products particularly if you go into the submicron or even nano range during drying the particles will definitely agglomerate again but depending on the final application this may not have an influence because we if it once have created the primary particles in the required finest they may be dispersed and in the following process I give an example which which is a polymer compounding we can grind the particles down dry them and if we dose them into the extruder for the polymers by the shear stress they can be d agglomerate it again to a certain to a certain particle size okay but drying is very difficult sizing with respect to the what size media should be used I guess again there might be there might be some generic approach to this not knowing exactly the material yeah but the particle size gives an indication and for a hundred nanometer product I would choose grinding media around 200 or 300 micron maybe a little a little bigger if we have the coarse feed material and maybe it’s necessary to switch into steps from coarser grinding media to fine grinding media but for a hundred nanometer product we usually do not need two very fine grinding media or 15 microns which cause finally big problems in the production process in the lab it’s okay but for production for for availability in the production and liability of the and availability of the process it’s difficult to operate bigness with 50 micron be okay basically what you’re saying is besides from the end product finest also basically yeah you can imagine if you if you have a 100 micron feed particle and you’ll have 100 micron beats it is not possible to crush the the big particles with the small beans if you if you want nano particles can you wet no then spray dry the slurry if this is one of the common methods to sprayed right and you create a glomer rates 200 micron which which have which have agglomeration forces which can be destroyed later on so it is a very soft agglomerate and if you put it for example into a ceramic casting then the primary particles will occur again

and grindin you speak about aluminum material to be ground yes 0.5 millimeters is too big for wet grinding we use the four four or five millimeters beats just for the drive vertical media mill for the wet medium use we are going down to two millimeters maximum preferably one millimeter or smaller seed size basically okay I think this is where we’re gonna stop with the question answer send live question answer session and what we will do as I mentioned is we have old all the additional questions that come in and you have seen our contact names on your screen as well in the US it’s North America dr. Stein and what we will do is we will contact you individually to provide you with the answers that you need thank you very much for joining us today