pursuant to the invention , the crude kaolin serving as the feed can typically comprise a hard grey crude of the type aforementioned , although other discolored kaolins can also be used . the grey crude typically has a g . e . brightness in the range of from about 75 to 85 and includes contaminant titania from about 0 . 5 up to 3 . 0 % by weight of kaolin . contaminant iron is also present , ranging up to about 2 % expressed as fe 2 o 3 . the particle size distribution of the crude is such that at least 85 % by weight of the particles are of less than 2 micrometers e . s . d . this crude is blunged and dispersed at about 70 % solids ( more generally it can be prepared as 30 to 70 % solids ). sodium carbonate and sodium hexametaphosphate can be used as dispersing agents . the resultant slurry is degritted as , for example , by being passed through a 20 mesh to 80 mesh screen . the slurry is then scalped , diluted to 35 to 40 % solids , and classified in centrifuges to produce a fraction at about 90 % less than 0 . 5 micron . typically , at least 90 % by weight of the particles are of less then 0 . 5 micrometers . this slurry is then subjected to an initial oxidative bleaching step preferably using sodium hypochlorite . the dosage of the hypochlorite is in the range of 0 . 5 to 3 gallons per ton of dry clay . the bleached slurry is typically aged overnight , i . e . for about 12 hours to 24 hours . the resulting slurry is thereupon diluted to about 5 to 25 % solids , typically around 10 to 12 % solids , and is then subjected to a selective flocculation treatment . the preferred selective flocculation reagents comprise a high molecular weight anionic polyacrylamide or a copolymer of a polyacrylate and polyacrylamide . a preferred flocculating agent is the calgon ™ r50 polymer which is a weakly anionic copolymer of polyacrylate and polyacrylamide , available from calgon corporation of pittsburgh , pa . concentrations of the flocculating polymer or copolymer will generally be in the range of 0 . 01 % to 0 . 1 %, ( or 0 . 3 to 5 lbs / ton dry clay ), with about 2 pounds per ton dry clay being typical . it may be noted here that the first oxidative bleaching step which proceeds selective flocculation not only bleaches sizable proportions of the organic discolorants , but has a synergistic effect in facilitating formation of the flocs during the subsequent selective flocculation . as a result of the selective flocculation , a supernatant phase forms which is highly concentrated in the contaminant titania . this supernatant phase is separated , and discarded or otherwise used . the purified flocs or sediment are preferably passed at about 30 % solids through a high shear pump which break up the flocs , whereupon they are subjected as an aqueous suspension to ozonation at a dosage level of 1 . 5 - 6 pounds , typically about 2 pounds per ton of kaolin of the ozone . the ozone is preferably applied as a stream of bubbles which can be passed upwardly through the slurry . this can be a batch process , but preferably is a continuous process in which the ozone bubbles pass counter current to a flow of the slurry in a pipe or other conduit , such as mixed and packed column . the ozone acts not only to destroy substantial portions of the remaining discoloring organics , but of equal importance , acts to destroy by oxidation the flocculent , i . e . the polymer which has been previously added . in consequence , the clay in the slurry is now in a dispersed phase and may be readily subjected to further beneficiation depending upon the contaminants . the slurry at about 30 % solids or other dilute condition is thus typically passed through a high intensity magnetic separator , using apparatus of the type described in u . s . pat . no . 3 , 627 , 678 . the beneficiated material emerging from the magnetic separation may then be subjected , as is known in the art , to conventional flocculation and reductive bleaching as , for example , by addition of sulfuric acid with sodium hydrosulfite and aluminum sulphate . the recovered and bleached material can then be dried , as by filtering on a rotary vacuum filter or the like , after which the material can be reslurried , dispersed , and then dried by spray drying or by an evaporator . the resulting material is found to be an excellent coating kaolin pigment having a brightness of at least 91 and preferably of at least 93 . it displays a hercules viscosity of less than 18 dynes of 4400 rpm when prepared as a 70 % solids coating slurry . the starting crude for this example was a fine hard grey kaolin from a mine near wrens , ga . this crude was processed by two methods . first , by the method described in the background of this invention as being used for producing conventional alphafine ®; and second , by means of the process of the invention . the initial crude was characterized by having a brightness of 84 . 6 , a tio 2 content of 2 . 03 % and an iron content of 0 . 87 % expressed as fe 2 o 3 . the conventionally processed material was found to have a brightness of 91 . 2 , a titania content of 1 . 47 %, and an iron content of 0 . 76 %. the sample processed by the method of the invention was found to have a much higher brightness of 93 . 3 , a much lower titania content of 0 . 47 % and a virtually similar iron content of 0 . 77 %. thus , the process of the invention was found with the same material to produce an improvement in brightness of 2 . 1 points , which is extremely significant in the pertinent art . the process of the invention is particularly significant in terms of maintaining the rheological properties of the starting material . previous art of the similar - type selective flocculation process has always resulted in a product with poor theology due to the residual contaminating flocculent , or the process could yield a product with comparable theology , but is economically unfeasible . this advantage of the present invention is illustrated in table a by a comparison between a conventionally processed product ( processed as for conventional alphafine ®-- see example 1 ) and a sample processed in accordance with the invention -- see example 1 . it would be noted that viscosity of the product of the invention is only slightly higher at low shear rate , and not much different at high shear rate . table a______________________________________ brookfield cps hercules dynesrheology : @ 20 rpm @ 4400 rpm______________________________________sample # 1conventionally 460 4 . 8processed productproduct of 530 6 . 7inventionsample # 2conventionally 220 4 . 1processed productproduct of 340 3 . 8invention______________________________________ although the present invention has been particularly set forth in terms of specific embodiments thereof , it will be understood in view of the instant disclosure , that numerous variations upon the invention are now enabled to those skilled in the art , which variations yet reside within the scope of the invention . accordingly , the invention is to be broadly construed , and limited only by the scope and spirit of the claims now appended hereto .