Mix sugar, salt, evaporated milk and butter in a heavy-bottomed saucepan. Cook over low heat, stirring constantly with a wooden spoon, until sugar dissolves. Stir in pecans and cook over medium heat until mixture reaches the soft ball stage. (234 to 240 degrees F on a candy thermometer; if you spoon a drop of boiling syrup into a cup of ice water, it will form a soft ball that flattens easily between your fingers.) Remove pan from heat and stir rapidly until mixture thickens. Drop pralines by teaspoonfuls, 1-inch apart onto parchment paper-lined baking sheets; let cool completely until firmed up. Store in an airtight container.