Mid-kiln injection of waste-derived materials

Abstract

A method for the production of cement clinker comprises the introduction of non-traditional materials into the kiln, preferably at a mid-kiln locations. The non-traditional materials are materials that are difficult, expensive or environmentally challenging for disposal. In one embodiment, weathered clinker is introduced into the kiln to admix with the raw material mix to augment clinker production. In another embodiment, bird, animal or human manure is added to the kiln so that gaseous reducing agents can be released by the manure and combine with certain noxious gases generated during the clinker production, to thereby reduce the noxious gas output. In other embodiments, other non-traditional waste-derived fuels are added to the kiln during clinker production, including railroad ties coated with creosote, industrial, commercial and consumer rubber components, such as rubber hoses, unshredded plastics, and organic materials, such as bird and animal meal.

1 - 4 . (canceled)  
   
   
       5 . A method for the production of cement clinker in a heated kiln having a feed end for receiving raw mix and a discharge end at which the clinker is discharged, comprising the step of introducing excrement or manure into the kiln prior to the discharge end of the kiln.  
   
   
       6 . The method for the production of cement clinker according to  claim 5 , wherein the manure is introduced into the kiln at a mid-kiln location.  
   
   
       7 . The method for the production of cement clinker according to  claim 6 , wherein the manure is introduced into the kiln at the calcining zone.  
   
   
       8 . The method for the production of cement clinker according to  claim 6 , wherein the manure is introduced into the kiln downstream of the calcining zone.  
   
   
       9 . A method for reducing a gas by-product discharged during the production of cement clinker in a heated kiln having a feed end for receiving raw mix and a discharge end at which the clinker is discharged, the kiln having a heating zone in which fuel is combusted to produce heat for the kiln and in which the combustion of the fuel produces a gas by-product that pass through the kiln, the method comprising the step of introducing a material into the kiln prior to the discharge end of the kiln, wherein the material is adapted to release a gaseous reducing agent when subjected to the heat within the kiln, the reducing agent reacting with the gas by-product.  
   
   
       10 . The method for reducing a gas by-product discharged during the production of cement clinker of  claim 9 , wherein the gas by-product is NO x  and the gaseous reducing agent is adapted to react with the NO x .  
   
   
       11 . The method for reducing a gas by-product discharged during the production of cement clinker of  claim 10 , wherein the gaseous reducing agent is ammonia.  
   
   
       12 . The method for reducing a gas by-product discharged during the production of cement clinker of  claim 11 , wherein the material is excrement or manure.  
   
   
       13 . A method for the production of cement clinker in a heated kiln having a feed end for receiving raw mix and a discharge end at which the clinker is discharged, comprising the step of introducing at a mid-kiln location of the kiln waste materials selected from the group of rubber hoses, recycled rubber products, unshredded plastics, and railroad ties that are coated in creosote.  
   
   
       14 . The method of  claim 13 , wherein the group further includes bird or animal meal.  
   
   
       15 . The method of  claim 14 , wherein the group further includes processed sludge.