Thermoplastic articles

Abstract

A process is provided for making thermoplastic-composites from recycled thermoplastics (polyolefins) together with phosphogypsum waste by-product from the phosphate fertilizer wet process or, in an equally preferred embodiment with fluorogypsum waste by-product from fluorine production wet process to produce lumber profiles. The process involves (a) admixing phosphogypsum (calcium sulfate) and/or fluorogypsum (calcium fluoride) waste byproduct and/or Flue Gas Desulfurization (FGD) gypsum and/or crude gypsum and/or calcined gypsum with thermoplastics and a functionalized compound with or without coupling agents to produce a filled thermoplastic-composite composition, and (b) melt processing the composition to produce a filled thermoplastic-composite article. The articles are preferably in the form of railroad cross ties or construction articles such as common lumber profiles, panels, tiles, poles, utility poles, crossarms for utility poles, roofing tiles, pipeline skids, pilings, marine fender-piles (including light emitting piles), bulkheads, revetments, and are useful for constructing various structures, such as oilfield board roads and equipment mats. The process avoids the accumulation of undesired phosphogypsum/fluorogypsum “stacks” and provides environmentally friendly useful products which require no chemical preservatives to prevent insect infestation or decay from the elements. Tailings from ore processing can also be used as a filler.

1 - 14 . (canceled) 
   
   
       15 . A thermoplastic-composite composition comprising:
 (a) a thermoplastic resin, and   (b) a calcium sulfate composition comprising a calcium sulfate present at a level of from 50 to 99 percent by weight based on the total weight of the calcium sulfate composition.   
   
   
       16 . The composition of  claim 15  wherein the thermoplastic resin is a polyolefin. 
   
   
       17 - 47 . (canceled) 
   
   
       48 . A marine piling comprising:
 (a) a core element comprising a thermoplastic composition comprising a thermoplastic resin and a filler, the core element having an outer surface; and   (b) a photoluminescent material adjacent the outer surface of the core element.   
   
   
       49 - 51 . (canceled) 
   
   
       52 . The piling of  claim 48  wherein the filler comprises calcium sulfate and/or calcium fluoride present at a level of from 40 to 99 percent by weight based on the total weight of the composition. 
   
   
       53 . The piling of  claim 52  wherein the thermoplastic resin of the core element is present at a level of from 40 to 75 percent by weight based on the total weight of the thermoplastic composition, and the calcium sulfate composition being present at a level of from 25 to 60 percent by weight based on the total weight of the thermoplastic composition of the core element. 
   
   
       54 - 56 . (canceled) 
   
   
       57 . The piling of  claim 48  wherein the photoluminescent material is zinc sulfide. 
   
   
       58 . The piling of  claim 57  wherein the zinc sulfide is in crystal form. 
   
   
       59 . The piling of  claim 57  wherein the photoluminescent material emits light bright enough and long enough that the piling is visible to a normal human eye at a far enough distance to be useful at night. 
   
   
       60 . The piling of  claim 57  wherein the photoluminescent material emits the bright enough light for at least four hours. 
   
   
       61 . The piling of  claim 57  wherein the photoluminescent material emits the bright enough light for about 4-10 hours. 
   
   
       62 - 64 . (canceled) 
   
   
       65 . A railroad tie made by melt processing a thermoplastic composition comprising:
 (a) a thermoplastic resin; and   (b) a calcium sulfate composition consisting essentially of a calcium sulfate present at a level of from 50 to 99 percent by weight based on the total weight of the calcium sulfate composition, and wherein the tie has substantially trapezoid-shape, a top and a bottom, and the bottom is broader than the top.   
   
   
       66 . The tie of  claim 65  wherein the thermoplastic resin is a polyolefin. 
   
   
       67 . The tie of  claim 65  wherein the thermoplastic composition includes the thermoplastic resin in an amount of from 40 to 75 percent by weight based on the total weight of the thermoplastic composition, the calcium sulfate composition in an amount of from 25 to 60 percent by weight based on the total weight of the thermoplastic composition. 
   
   
       68 . The tie of  claim 65  wherein the tie include holes for receiving carriage bolts for securing rail to the tie. 
   
   
       69 . The tie of  claim 65  wherein the composition comprises a yellow colorant. 
   
   
       70 . The railroad tie of  claim 65 , wherein the melt processing is extrusion under high shear pressure. 
   
   
       71 . A process for making a railroad track, the process comprising:
 (a) providing a plurality of the ties of  claim 65 ;   (b) laying the ties on a raised rail bed; and   (c) placing rail on the ties.   
   
   
       72 . The process of  claim 71  wherein the composition comprises a yellow colorant. 
   
   
       73 . The process of  claim 71  wherein the ties include holes for receiving carriage bolts for securing the rail to the ties. 
   
   
       74 . A product made by the process of  claim 71 .