Soil conditioning agglomerates containing calcium

Abstract

Mechanically strong, water-disintegrable agglomerates made from a particulate calcium source, a water-soluble binder and optionally containing a primary plant nutrient source and/or micronutrient source and a process for forming such agglomerates are disclosed. The agglomerates may be used as a soil liming agent and for introducing nutrient values into cultivated soil. Also disclosed is a method for introducing nutrient values into cultivated soil so as to inhibit leaching of the nutrient values from the soil and improve utilization of the nutrient values by plants grown in the soil.

1 - 31 . (canceled)  
   
   
       32 . An agglomerate for use as a soil conditioner, the agglomerate being formed by pelletizing a preagglomerate containing a water-soluble binder selected from the group consisting of lignosulonates, lignosulfonate salts, polyvinyl alcohol, polyacrylic acid salts, amylose, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, ethylhydroxyethylcellulose, corn starch, wheat starch, molasses and mixtures thereof and a particulate calcium source selected from the group consisting of limestone, dolomitic limestone, gypsum, hydrated lime and mixtures thereof, the particulate calcium source having a particle size distribution such that less than about 1% by weight of the particulate calcium source is +20 mesh, less than about 10% by weight of the particulate calcium source is −20 +100 mesh and at least about 90% by weight of the particulate calcium source is −325 mesh Tyler Standard Sieve Series, the agglomerate comprising at least about 15% by weight of the particulate calcium source and exhibiting an average green crush strength of at least about 2 pounds when sized to from −7 to +8 mesh Tyler Standard Sieve Series.  
   
   
       33 . An agglomerate as set forth in  claim 32  wherein the particulate calcium source is selected from the group consisting of limestone, dolomitic limestone, gypsum and mixtures thereof.  
   
   
       34 . An agglomerate as set forth in  claim 33  wherein the particulate calcium source has a particle size distribution such that at least about 90% by weight of the particulate calcium source is −400 mesh Tyler Standard Sieve Series.  
   
   
       35 . An agglomerate as set forth in  claim 34  wherein the amount of water-soluble binder present in the preagglomerate is at least about 1% by weight (dry basis).  
   
   
       36 . An agglomerate as set forth in  claim 35  wherein the amount of water-soluble binder present in the preagglomerate is at least about 2% by weight (dry basis).  
   
   
       37 . An agglomerate as set forth in  claim 34  wherein the water-soluble binder is selected from the group consisting of lignosulfonate, lignosulfonate salts and mixtures thereof.  
   
   
       38 . An agglomerate as set forth in  claim 37  wherein the amount of water-soluble binder present in the preagglomerate is at least about 1% by weight (dry basis).  
   
   
       39 . An agglomerate as set forth in  claim 38  wherein the amount of water-soluble binder present in the preagglomerate is at least about 2% by weight (dry basis).  
   
   
       40 . An agglomerate as set forth in  claim 34  wherein the size of the agglomerate is from −3 to +40 mesh Tyler Standard Sieve Series.  
   
   
       41 . An agglomerate as set forth in  claim 34  wherein the combined concentration of CaO and Ca(OH) 2  in the particulate calcium source is at least about 3% by weight.  
   
   
       42 . An agglomerate as set forth in  claim 34  wherein the magnesium content of the agglomerate is no greater than about 2.5% by weight.  
   
   
       43 . An agglomerate as set forth in  claim 42  wherein the magnesium content of the agglomerate is no greater than about 1.5% by weight.  
   
   
       44 . An agglomerate as set forth in  claim 34  wherein the primary plant nutrient source functions as the water-soluble binder.  
   
   
       45 . A process for forming an agglomerate for use as a soil conditioning agent, the process comprising: 
 preparing a preagglomerate containing a water-soluble binder selected from the group consisting of lignosulonates, lignosulfonate salts, polyvinyl alcohol, polyacrylic acid salts, amylose, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, ethylhydroxyethylcellulose, corn starch, wheat starch, molasses and mixtures thereof and a particulate calcium source selected from the group consisting of limestone, dolomitic limestone, gypsum, hydrated lime and mixtures thereof, the particulate calcium source having a particle size distribution such that less than about 1% by weight of the particulate calcium source is +20 mesh, less than about 10% by weight of the particulate calcium source is −20 +100 mesh and at least about 90% by weight of the particulate calcium source is −325 mesh Tyler Standard Sieve Series; and    pelletizing the preagglomerate to form the agglomerate, the proportion of the particulate calcium source in the preagglomerate being sufficient such that the agglomerate comprises at least about 15% by weight of the particulate calcium source.    
   
   
       46 . A process as set forth in  claim 45  wherein the particulate calcium source is selected from the group consisting of limestone, dolomitic limestone, gypsum and mixtures thereof.  
   
   
       47 . A process as set forth in  claim 46  wherein the particulate calcium source has a particle size distribution such that at least about 90% by weight of the particulate calcium source is −400 mesh Tyler Standard Sieve Series.  
   
   
       48 . A process as set forth in  claim 47  wherein the amount of water-soluble binder present in the preagglomerate is at least about 1% by weight (dry basis).  
   
   
       49 . A process as set forth in  claim 48  wherein the amount of water-soluble binder present in the preagglomerate is at least about 2% by weight (dry basis).  
   
   
       50 . A process as set forth in  claim 47  wherein the water-soluble binder is combined with the other components of the preagglomerate as an aqueous solution of the binder.  
   
   
       51 . A process as set forth in  claim 47  wherein the water-soluble binder is selected from the group consisting of lignosulfonate, lignosulfonate salts and mixtures thereof.  
   
   
       52 . A process as set forth in  claim 51  wherein the amount of water-soluble binder present in the preagglomerate is at least about 1% by weight (dry basis).  
   
   
       53 . A process as set forth in  claim 52  wherein the amount of water-soluble binder present in the preagglomerate is at least about 2% by weight (dry basis).  
   
   
       54 . A process as set forth in  claim 51  wherein the water-soluble binder is combined with the other components of the preagglomerate as an aqueous solution of the binder.  
   
   
       55 . A process as set forth in  claim 54  wherein the water-soluble binder comprises a lignosulfonate salt and the aqueous solution of the binder contains from about 48% to about 60% by weight solids.  
   
   
       56 . A process as set forth in  claim 47  wherein the size of the agglomerate is from −3 to +40 mesh Tyler Standard Sieve Series.  
   
   
       57 . A process as set forth in  claim 47  wherein the combined concentration of CaO and Ca(OH) 2  in the particulate calcium source is at least about 3% by weight.  
   
   
       58 . A process as set forth in  claim 47  wherein the concentration of magnesium-containing compounds in the preagglomerate is such that the magnesium content of the agglomerate is no greater than about 2.5% by weight.  
   
   
       59 . A process as set forth in  claim 58  wherein the concentration of magnesium-containing compounds in the preagglomerate is such that the magnesium content of the agglomerate is no greater than about 1.5% by weight.  
   
   
       60 . A process as set forth in  claim 47  wherein the primary plant nutrient source functions as the water-soluble binder.