14 Mining Ne w Opportunities Flot a tion is t he mo st c ommon me t ho d of s e para ting me t als Te ne ly g r ound or e is mi x e d w it h w a t er t o f or m a s lu r r y Cer t ain c hemic als t ha t c oa t only t he de sir e d or e mineral c om p onen t s ar e adde d in small amoun t s R ising air bubble s c a pt ur e t he c oa t e d mineral par tic le s and oa t t hem t o t he sur f ac e wher e t he y ar e sk imme d o t o a s e para t e pr o c e ss Te s e c onc en tra t e d minerals ar e f ur t her r ene d t o pr o duc e pur e me t al in a pr o c e ss c alle d smelti ng Onc e t he v alua ble me t als ha ve b e en s e para t e d or c onc en tra t e d t he lef t over ma t er ials r o c k f rag men t s dust and c hemic als ar e c alle d t ailing s Mining c om panie s wor k har d t o ensur e t ha t t he s e t ailing s ar e manag e d e e ctive ly and r e sp onsibly S uc h e or t s ar e ne c e ssar y b e c a us e t he t ailing s ma y c on t ain dang er ous c hemic als t ha t c ould le ak in t o str e ams and lak e s Mine t ailing s ar e k e pt in sp e c ially de sig ne d p onds or c e lls Te ba s e of t he c e ll is line d w it h he a v y pla stic or dens e c la y An y w a t er le a v ing t he p ond is tr e a t e d t o r emove ac ids or dang er ous c hemic als Te t ailing s ar e e ven t ually c over e d w it h s oil and plan t e d w it h g ra ss and tr e e s S tr ict g over nmen t r ule s ar e a pplie d t o t ailing s S ome mining c om panie s ha ve e ven str ict er in t er nal r ule s D i amond s ar e D ie r e nt Te diamond r e c over y pr o c e ss is s ome wha t di er en t Te or e is not g r ound or c r ushe d t o a ne p owder b e c a us e t his pr o c e ss would de str oy t he diamonds Diamonds ha ve a ver y high density w h i c h m e a n s t h e y c a n b e s o r t e d o u t f r o m t h e w a s t e r o c k b y d e n s i t y s u s p e n s i o n I n t h i s p r o c e s s t h e d i a m o n d b e a r i n g r o c k i s m i x e d w i t h a m u d d y w a t e r s u s p e n s i o n a n d s t i r r e d b y r o t a t i n g b l a d e s T e h e a v i e r m a t e r i a l s i n c l u d i n g t h e d i a m o n d s s e t t l e t o t h e b o t t o m w h i l e t h e l i g h t e r w a s t e r i s e s t o t h e t o p T e d i a m o n d s a r e s o r t e d o u t f r o m t h e o r e c o n c e n t r a t e u s i n g e i t h e r a g r e a s e t a b l e o r a n x r a y s o r t e r G re a s e T able Diamonds r e p e l w a t er but ar e a t tract e d t o g r e a s e An e a s y w a y t o pic k out t he diamonds is t o ush t he c onc en tra t e w it h w a t er over a sur f ac e c over e d w it h g r e a s e c alle d a g r e a s e t a ble Te diamonds stic k t o t he g r e a s e while t he w a st e de br is is w a she d a w a y X r a y S ome diamonds ar e uor e s c en t Tis me ans t ha t when diamonds ar e e x p o s e d t o ultra v iole t ligh t t he diamond c an a b s or b t he highener g y radia tion and r eemit it a s v isible ligh t An x ra y s or t er t ak e s adv an t ag e of t his pr op er ty When diamonds uor e s c e w it h e x p o sur e t o x ra ys a s or t er de t e ct s t he uor e s c enc e and tr igg ers a j e t of air whic h pr op e ls t he diamond in t o a c olle ction b o x M i ne C lo su re and Re cl ama tion Mining is a t em p orar y us e of t he land no mine w ill la st f or e ver I t is an im p or t an t g oal of mining c om panie s t o r e t ur n t heir mining sit e s t o a na t ural and st a ble st a t e mak ing t hem a v aila ble f or ot her us e s W h e n u n d e r gr o u n d a n d o p e n p i t m i n e s a r e c l o s e d t h e s i t e s n e e d t o b e r e s t o r e d c l o s e t o t h e i r o r i gi n a l s t a t e Re cl ama tion r ef ers t o r e st or ing t he land t o a st a t e t ha t is saf e st a ble and pr o ductive and na t urally blends w it h t he sur r ounding en v ir onmen t Tis pr o c e ss of t en o c curs in nor t her n On t ar io wher e g old c opp er and nic k e l mine s ar e c ommon Re c lama tion in volve s r emov ing all t he building s and e q uipmen t tr e a ting t he mine t ailing s or w a st e w a t er st a bili z ing t he under g r ound wor k ing s or op en pit s and c lo sing t he mine shaf t s and t unne ls E x c a v a t e d ar e a s and op en pit s m ust b e lle d in w it h w a t er sand c emen t or w a st e r o c k Te small ar e a s t ha t wer e us e d f or t he building s ar e r e plan t e d w it h g ra ss and tr e e s Le ar n i ng A ct iv it y 11 Explor e the Mining P r oc ess Student Handout 4 of 4