CIM What ar e some simple doable things mines can do right now to impr ove mill ef ficiency Bouchar d Design a pr oper contr ol str at egy T he very basic ones would allow y ou t o r each a st eady oper ation and maint ain it T his is not alw ays done pr operly Bef or e I became a pr of es sor in 2012 I work ed f or a f e w y ears in the industry A very g ood friend of mine Eduar do Nune z and I wer e working in the same plac e in the pr oc es s contr ol gr oup He w as doing a pr oject in a mill and he implement ed a very sim ple contr ol str at egy E v ery thing w as alr eady in plac e ther e T h e most basic contr ols we used PIDs pr oportional int egr al deriv ative contr ollers wer e just looking at density measur ement s downstr eam the h y dr ocy clones and the level in the pump bo x of the grinding cir cuit and just doing so he decr eased the kilo w a t t s per t onne by seven t o eight per c ent It w as not a very sophisticat ed pr oject T his w as something very simple It can be done T he plant s alr eady ha ve the har dw ar e t o do it T h ey may lack the inhouse expertise t o do it but we ha ve consult ant s ar ound that can do that CIM If plant managers want to impr ove their pr ocess contr ol systems and pr ocedur es wher e do they start Bouchar d T her e s a guy at BB A Michel Ruel He s very wise and he alw ays says Do y our housek eeping f i rst So look at every thing y o u ve g ot implement ed alr eady and mak e sur e it works up t o y our expect ations Just doing that will pr obably bring y ou 50 or 60 per c ent of the benef it s But y ou need people who ar e able t o underst and contr ollers and mak e them work pr operly Quit e of t en it s har d t o f ind the right people in the plant t o do that Sinc e the plant is running oper at ors will put the contr ols in man ual handle the plant the best they can and at the end of the day they will pr obably mak e their budg et an y w ay T hen they ll say I don t need the contr oller So st art fr om the basics check all y our contr ollers mak e sur e all y our instrument ation is working f ine and mak e sur e ther e ar e no conf igur ation pr oblems in y our contr ol s y st em because that is a very common pr oblem CIM What is the next step Bouchar d It s funn y Lot s of people do the next st ep as the f i rst st ep T h ey will look t o t echnology In all the plant s ther e ar e nor mally two types of industrial contr oller the pr ogr ammable logic contr oller PLC and sometimes y ou will ha ve a distribut ed con tr ol s y st em DC S as well In the early days they wer e very diff er ent t echnologies N o w they both do a bit of what the other does Some plant s will still ha ve PLC f or the basic contr ol lay er and then they will add the DC S f or a second lay e r but now we can as sume all the plant s work either on one or the two s y st ems and they should ha ve this f i rst t echnology lay er working pr operly F or the second st ep people look at mor e t echnology Inst ead of doing the housek eeping they will st art right off the bat with model pr edictive contr ol MP C t echnology T o do that y ou need t o pur chase a new s y st em y ou need new har dw ar e P r edictive contr ol t echnology is very powerful W e do lot s of applications in our r esear ch using this It has been used f or decades in the oil and g as busines s and it works f ine It s very sophisticat ed and it let s y ou do lot s of thing s y ou can t do with PID contr ollers What people lik e about pr edictive contr ol t echnology is that it s kind of a black bo x that does magic and can mak e some pr edictions People think it will solve all their pr oblems If y ou st art with that on a shak y f oundation it ain t g oing t o work People see that and then they pull the plug and say that contr ol doesn t work But if y ou did y our housek eeping pr operly the second lay er is when it s time t o think about MP C W ith MP C y ou can ha ve actual mathematical optimizing done Imagine a bell shaped curve with the peak of the curve being up with optimiz ation y ou ha ve a mathematical function and y ou ar e trying t o f ind the peak of it and what will bring y o u t o the peak T his is what we call f orm optimiz ation in the sense that y ou ar e not just trying t o do bet t e r Y ou ar e trying t o f ind the best point of the curve wher e y ou ar e g oing t o be oper ating at the highest thr oughput or the highest pr of it or what ever T he contr oller has a cost function T he cost function will be def ined as y ou will meaning y ou can set the contr olled v ariable t o be at a set point So y ou add the thr oughput t o the cost func tion As long as y ou ar e incr easing the thr oughput y our cost will be g oing down So at every contr ol int erv al say every two sec onds the optimiz ation r outine will be trying t o f ind what ar e the best conditions that will bring y ou t o y our lowest cost T h at s what can be done with MP C When y ou do MP C as well it s time t o look at new sensors I w as t alking bef or e about siz e distribution sensors so this is when y o u d st art implementing those Y ou may w ant t o think about sensors on y our or e f eed Y ou can ha ve a camer a on y our con vey or trying t o estimat e y our siz e distribution or even the cont ent of y our or e in t erms of gr ades Onc e y ou g o ther e the next st ep is what we call r eal time optimiz ation Real time optimiz ation is still doing optimiz ation but it s not doing it dynamically It will look at optimal oper ating conditions in t erms of what the mark et is doing what is the pric e of the conc entr at e on the mark et what z one of y our mine y ou should be exploiting now Real time optimiz ation is not ex e cut ed every second or every minut e It will be looking at it mor e lik e every day or every shif t so it s les s fr equent CIM What level ar e most pr ocessing plants at Bouchar d Real time optimiz ation is still the Holy Gr ail I don t think an ybody is doing it Perhaps in oil and g a s but I ha ven t seen an y applications Most ar e still at st ep one the housek eeping st ag e E v en ther e ther e ar e diff er ent types of lay e rs Some plant s ar e doing very well and I underst and wh y they ar en t doing mor e because they r e happy with what they ve g ot and that s f ine F or the second st ep we ar e st arting t o see some applications I know Agnico Eagle implement ed some MP C contr ollers in their grinding cir cuit s I think it w as two y ears ag o I ha ven t seen the r esult s but appar ently they ar e very satisf ied with them T he types of plant s that ar e doing the second t echnological level pr et ty well ar e still r a r e And even the f i rst level done well is r a r e One point Ive mentioned bef or e is t o mak e the most out of what y ou ha ve at hand bef or e trying t o pur chase new har dw ar e g ear equipment Try t o see if y ou ar e using what y ou ha ve t o the maximum ext ent Ask am I g e t ting all the benef it s I am sup posed t o g et fr om it I think that s alw ays the f i rst st ep y o u should t a k e and by doing so y ou sa ve money and y ou in vest in people because a lot of people will be developing applications using y our equipment y our f acilities Y ou ar e tr aining y our peo ple as well so y o u r e working on the human as set and not just on the equipment as set side of thing s T h at should be ther e I think it s the most import ant thing and it s sometimes mis sed by some people because it s not sexy CIM MayJune 2020 MaiJuin 2020 39 ener gy efciency